[GitHub] [beam] boyuanzz commented on a change in pull request #12581: [BEAM-10378] Add Azure Blob Storage Filesystem

[GitBox <gi...@apache.org>]

boyuanzz commented on a change in pull request #12581:
URL: https://github.com/apache/beam/pull/12581#discussion_r471195136



##########
File path: sdks/java/io/azure/src/main/java/org/apache/beam/sdk/io/azure/blobstore/AzfsResourceId.java
##########
@@ -156,8 +190,6 @@ public int hashCode() {
   @Override
   public ResourceId resolve(String other, ResolveOptions resolveOptions) {
     checkState(isDirectory(), "Expected this resource to be a directory, but was [%s]", toString());
-    // TODO: check if resolve options are an illegal name in any way, see:

Review comment:
       Is this resolved now?

##########
File path: sdks/java/io/azure/src/main/java/org/apache/beam/sdk/io/azure/blobstore/AzureBlobStoreFileSystem.java
##########
@@ -17,67 +17,438 @@
  */
 package org.apache.beam.sdk.io.azure.blobstore;
 
+import static java.nio.channels.Channels.newChannel;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkNotNull;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkState;
+
+import com.azure.core.http.rest.PagedIterable;
+import com.azure.storage.blob.BlobClient;
+import com.azure.storage.blob.BlobContainerClient;
+import com.azure.storage.blob.BlobServiceClient;
+import com.azure.storage.blob.BlobServiceClientBuilder;
+import com.azure.storage.blob.models.BlobItem;
+import com.azure.storage.blob.models.BlobProperties;
+import com.azure.storage.blob.models.BlobStorageException;
+import com.azure.storage.blob.models.ListBlobsOptions;
+import com.microsoft.azure.storage.CloudStorageAccount;
+import com.microsoft.azure.storage.SharedAccessAccountPolicy;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
+import java.time.Duration;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Date;
+import java.util.Iterator;
 import java.util.List;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 import org.apache.beam.sdk.io.FileSystem;
+import org.apache.beam.sdk.io.azure.options.BlobstoreClientBuilderFactory;
+import org.apache.beam.sdk.io.azure.options.BlobstoreOptions;
 import org.apache.beam.sdk.io.fs.CreateOptions;
 import org.apache.beam.sdk.io.fs.MatchResult;
+import org.apache.beam.sdk.util.InstanceBuilder;
 import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Supplier;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Suppliers;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.FluentIterable;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableSet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class AzureBlobStoreFileSystem extends FileSystem<AzfsResourceId> {
 
+  private static final Logger LOG = LoggerFactory.getLogger(AzureBlobStoreFileSystem.class);
+
+  private static final ImmutableSet<String> NON_READ_SEEK_EFFICIENT_ENCODINGS =
+      ImmutableSet.of("gzip");
+
+  private Supplier<BlobServiceClient> client;
+  private final BlobstoreOptions options;
+
+  AzureBlobStoreFileSystem(BlobstoreOptions options) {
+    this.options = checkNotNull(options, "options");
+
+    BlobServiceClientBuilder builder =
+        InstanceBuilder.ofType(BlobstoreClientBuilderFactory.class)
+            .fromClass(options.getBlobstoreClientFactoryClass())
+            .build()
+            .createBuilder(options);
+
+    // The Supplier is to make sure we don't call .build() unless we are actually using Azure.
+    client = Suppliers.memoize(builder::buildClient);
+  }
+
+  @VisibleForTesting
+  void setClient(BlobServiceClient client) {
+    this.client = Suppliers.ofInstance(client);
+  }
+
+  @VisibleForTesting
+  BlobServiceClient getClient() {
+    return client.get();
+  }
+
   @Override
   protected String getScheme() {
-    return "azfs";
+    return AzfsResourceId.SCHEME;
   }
 
   @Override
-  protected List<MatchResult> match(List<String> specs) throws IOException {
-    // TODO
-    return null;
+  protected List<MatchResult> match(List<String> specs) {
+    List<AzfsResourceId> paths =
+        specs.stream().map(AzfsResourceId::fromUri).collect(Collectors.toList());
+    List<AzfsResourceId> globs = new ArrayList<>();
+    List<AzfsResourceId> nonGlobs = new ArrayList<>();
+    List<Boolean> isGlobBooleans = new ArrayList<>();
+
+    for (AzfsResourceId path : paths) {
+      if (path.isWildcard()) {
+        globs.add(path);
+        isGlobBooleans.add(true);
+      } else {
+        nonGlobs.add(path);
+        isGlobBooleans.add(false);
+      }
+    }
+
+    Iterator<MatchResult> globMatches = matchGlobPaths(globs).iterator();
+    Iterator<MatchResult> nonGlobMatches = matchNonGlobPaths(nonGlobs).iterator();
+
+    ImmutableList.Builder<MatchResult> matchResults = ImmutableList.builder();
+    for (Boolean isGlob : isGlobBooleans) {
+      if (isGlob) {
+        checkState(globMatches.hasNext(), "Expect globMatches has next.");
+        matchResults.add(globMatches.next());
+      } else {
+        checkState(nonGlobMatches.hasNext(), "Expect nonGlobMatches has next.");
+        matchResults.add(nonGlobMatches.next());
+      }
+    }
+    checkState(!globMatches.hasNext(), "Expect no more elements in globMatches.");
+    checkState(!nonGlobMatches.hasNext(), "Expect no more elements in nonGlobMatches.");
+
+    return matchResults.build();
+  }
+
+  /**
+   * Expands glob expressions to regular expressions.
+   *
+   * @param globExp the glob expression to expand
+   * @return a string with the regular expression this glob expands to
+   */
+  @VisibleForTesting
+  static String wildcardToRegexp(String globExp) {
+    StringBuilder dst = new StringBuilder();
+    char[] src = globExp.replace("**/*", "**").toCharArray();
+    int i = 0;
+    while (i < src.length) {
+      char c = src[i++];
+      switch (c) {
+        case '*':
+          // One char lookahead for **
+          if (i < src.length && src[i] == '*') {
+            dst.append(".*");
+            ++i;
+          } else {
+            dst.append("[^/]*");
+          }
+          break;
+        case '?':
+          dst.append("[^/]");
+          break;
+        case '.':
+        case '+':
+        case '{':
+        case '}':
+        case '(':
+        case ')':
+        case '|':
+        case '^':
+        case '$':
+          // These need to be escaped in regular expressions
+          dst.append('\\').append(c);
+          break;
+        case '\\':
+          i = doubleSlashes(dst, src, i);
+          break;
+        default:
+          dst.append(c);
+          break;
+      }
+    }
+    return dst.toString();
+  }
+
+  private static int doubleSlashes(StringBuilder dst, char[] src, int i) {
+    // Emit the next character without special interpretation
+    dst.append("\\\\");
+    if ((i - 1) != src.length) {
+      dst.append(src[i]);
+      i++;
+    } else {
+      // A backslash at the very end is treated like an escaped backslash
+      dst.append('\\');
+    }
+    return i;
+  }
+
+  private List<MatchResult> matchGlobPaths(List<AzfsResourceId> globs) {
+    return FluentIterable.from(globs).transform(this::expand).toList();
+  }
+
+  /** Expands a pattern into {@link MatchResult}. */
+  @VisibleForTesting
+  MatchResult expand(AzfsResourceId azfsPattern) {
+
+    checkArgument(azfsPattern.isWildcard(), "is Wildcard");

Review comment:
       Can you elaborate more on the error msg? Like `the pattern should be wildcard`?

##########
File path: sdks/java/io/azure/src/main/java/org/apache/beam/sdk/io/azure/blobstore/AzfsResourceId.java
##########
@@ -93,6 +101,22 @@ public String getScheme() {
     return SCHEME;
   }
 
+  Optional<Long> getSize() {

Review comment:
       I think you can return `Long` directly and the caller should check whether it's `null`.

##########
File path: sdks/java/io/azure/src/main/java/org/apache/beam/sdk/io/azure/blobstore/AzureBlobStoreFileSystem.java
##########
@@ -17,67 +17,438 @@
  */
 package org.apache.beam.sdk.io.azure.blobstore;
 
+import static java.nio.channels.Channels.newChannel;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkNotNull;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkState;
+
+import com.azure.core.http.rest.PagedIterable;
+import com.azure.storage.blob.BlobClient;
+import com.azure.storage.blob.BlobContainerClient;
+import com.azure.storage.blob.BlobServiceClient;
+import com.azure.storage.blob.BlobServiceClientBuilder;
+import com.azure.storage.blob.models.BlobItem;
+import com.azure.storage.blob.models.BlobProperties;
+import com.azure.storage.blob.models.BlobStorageException;
+import com.azure.storage.blob.models.ListBlobsOptions;
+import com.microsoft.azure.storage.CloudStorageAccount;
+import com.microsoft.azure.storage.SharedAccessAccountPolicy;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
+import java.time.Duration;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Date;
+import java.util.Iterator;
 import java.util.List;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 import org.apache.beam.sdk.io.FileSystem;
+import org.apache.beam.sdk.io.azure.options.BlobstoreClientBuilderFactory;
+import org.apache.beam.sdk.io.azure.options.BlobstoreOptions;
 import org.apache.beam.sdk.io.fs.CreateOptions;
 import org.apache.beam.sdk.io.fs.MatchResult;
+import org.apache.beam.sdk.util.InstanceBuilder;
 import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Supplier;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Suppliers;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.FluentIterable;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableSet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class AzureBlobStoreFileSystem extends FileSystem<AzfsResourceId> {

Review comment:
       Please have a class-level javadoc to explain what the class is for.

##########
File path: sdks/java/io/azure/src/main/java/org/apache/beam/sdk/io/azure/blobstore/AzureBlobStoreFileSystem.java
##########
@@ -17,67 +17,438 @@
  */
 package org.apache.beam.sdk.io.azure.blobstore;
 
+import static java.nio.channels.Channels.newChannel;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkNotNull;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkState;
+
+import com.azure.core.http.rest.PagedIterable;
+import com.azure.storage.blob.BlobClient;
+import com.azure.storage.blob.BlobContainerClient;
+import com.azure.storage.blob.BlobServiceClient;
+import com.azure.storage.blob.BlobServiceClientBuilder;
+import com.azure.storage.blob.models.BlobItem;
+import com.azure.storage.blob.models.BlobProperties;
+import com.azure.storage.blob.models.BlobStorageException;
+import com.azure.storage.blob.models.ListBlobsOptions;
+import com.microsoft.azure.storage.CloudStorageAccount;
+import com.microsoft.azure.storage.SharedAccessAccountPolicy;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
+import java.time.Duration;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Date;
+import java.util.Iterator;
 import java.util.List;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 import org.apache.beam.sdk.io.FileSystem;
+import org.apache.beam.sdk.io.azure.options.BlobstoreClientBuilderFactory;
+import org.apache.beam.sdk.io.azure.options.BlobstoreOptions;
 import org.apache.beam.sdk.io.fs.CreateOptions;
 import org.apache.beam.sdk.io.fs.MatchResult;
+import org.apache.beam.sdk.util.InstanceBuilder;
 import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Supplier;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Suppliers;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.FluentIterable;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableSet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class AzureBlobStoreFileSystem extends FileSystem<AzfsResourceId> {
 
+  private static final Logger LOG = LoggerFactory.getLogger(AzureBlobStoreFileSystem.class);
+
+  private static final ImmutableSet<String> NON_READ_SEEK_EFFICIENT_ENCODINGS =
+      ImmutableSet.of("gzip");
+
+  private Supplier<BlobServiceClient> client;
+  private final BlobstoreOptions options;
+
+  AzureBlobStoreFileSystem(BlobstoreOptions options) {
+    this.options = checkNotNull(options, "options");
+
+    BlobServiceClientBuilder builder =
+        InstanceBuilder.ofType(BlobstoreClientBuilderFactory.class)
+            .fromClass(options.getBlobstoreClientFactoryClass())
+            .build()
+            .createBuilder(options);
+
+    // The Supplier is to make sure we don't call .build() unless we are actually using Azure.
+    client = Suppliers.memoize(builder::buildClient);
+  }
+
+  @VisibleForTesting
+  void setClient(BlobServiceClient client) {
+    this.client = Suppliers.ofInstance(client);
+  }
+
+  @VisibleForTesting
+  BlobServiceClient getClient() {
+    return client.get();
+  }
+
   @Override
   protected String getScheme() {
-    return "azfs";
+    return AzfsResourceId.SCHEME;
   }
 
   @Override
-  protected List<MatchResult> match(List<String> specs) throws IOException {
-    // TODO
-    return null;
+  protected List<MatchResult> match(List<String> specs) {
+    List<AzfsResourceId> paths =
+        specs.stream().map(AzfsResourceId::fromUri).collect(Collectors.toList());
+    List<AzfsResourceId> globs = new ArrayList<>();
+    List<AzfsResourceId> nonGlobs = new ArrayList<>();
+    List<Boolean> isGlobBooleans = new ArrayList<>();
+
+    for (AzfsResourceId path : paths) {
+      if (path.isWildcard()) {
+        globs.add(path);
+        isGlobBooleans.add(true);
+      } else {
+        nonGlobs.add(path);
+        isGlobBooleans.add(false);
+      }
+    }
+
+    Iterator<MatchResult> globMatches = matchGlobPaths(globs).iterator();
+    Iterator<MatchResult> nonGlobMatches = matchNonGlobPaths(nonGlobs).iterator();
+
+    ImmutableList.Builder<MatchResult> matchResults = ImmutableList.builder();
+    for (Boolean isGlob : isGlobBooleans) {
+      if (isGlob) {
+        checkState(globMatches.hasNext(), "Expect globMatches has next.");
+        matchResults.add(globMatches.next());
+      } else {
+        checkState(nonGlobMatches.hasNext(), "Expect nonGlobMatches has next.");
+        matchResults.add(nonGlobMatches.next());
+      }
+    }
+    checkState(!globMatches.hasNext(), "Expect no more elements in globMatches.");
+    checkState(!nonGlobMatches.hasNext(), "Expect no more elements in nonGlobMatches.");
+
+    return matchResults.build();
+  }
+
+  /**
+   * Expands glob expressions to regular expressions.
+   *
+   * @param globExp the glob expression to expand
+   * @return a string with the regular expression this glob expands to
+   */
+  @VisibleForTesting
+  static String wildcardToRegexp(String globExp) {
+    StringBuilder dst = new StringBuilder();
+    char[] src = globExp.replace("**/*", "**").toCharArray();
+    int i = 0;
+    while (i < src.length) {
+      char c = src[i++];
+      switch (c) {
+        case '*':
+          // One char lookahead for **
+          if (i < src.length && src[i] == '*') {
+            dst.append(".*");
+            ++i;
+          } else {
+            dst.append("[^/]*");
+          }
+          break;
+        case '?':
+          dst.append("[^/]");
+          break;
+        case '.':
+        case '+':
+        case '{':
+        case '}':
+        case '(':
+        case ')':
+        case '|':
+        case '^':
+        case '$':
+          // These need to be escaped in regular expressions
+          dst.append('\\').append(c);
+          break;
+        case '\\':
+          i = doubleSlashes(dst, src, i);
+          break;
+        default:
+          dst.append(c);
+          break;
+      }
+    }
+    return dst.toString();
+  }
+
+  private static int doubleSlashes(StringBuilder dst, char[] src, int i) {
+    // Emit the next character without special interpretation
+    dst.append("\\\\");
+    if ((i - 1) != src.length) {
+      dst.append(src[i]);
+      i++;
+    } else {
+      // A backslash at the very end is treated like an escaped backslash
+      dst.append('\\');
+    }
+    return i;
+  }
+
+  private List<MatchResult> matchGlobPaths(List<AzfsResourceId> globs) {
+    return FluentIterable.from(globs).transform(this::expand).toList();
+  }
+
+  /** Expands a pattern into {@link MatchResult}. */
+  @VisibleForTesting
+  MatchResult expand(AzfsResourceId azfsPattern) {
+
+    checkArgument(azfsPattern.isWildcard(), "is Wildcard");
+    String blobPrefix = azfsPattern.getBlobNonWildcardPrefix();
+    Pattern wildcardAsRegexp = Pattern.compile(wildcardToRegexp(azfsPattern.getBlob()));
+
+    LOG.debug(
+        "matching files in container {}, prefix {} against pattern {}",
+        azfsPattern.getContainer(),
+        blobPrefix,
+        wildcardAsRegexp.toString());
+
+    ListBlobsOptions listOptions = new ListBlobsOptions().setPrefix(blobPrefix);
+    Duration timeout = Duration.ZERO.plusMinutes(1);
+
+    String account = azfsPattern.getAccount();
+    String container = azfsPattern.getContainer();
+    BlobContainerClient blobContainerClient = client.get().getBlobContainerClient(container);
+    PagedIterable<BlobItem> blobs = blobContainerClient.listBlobs(listOptions, timeout);
+    List<MatchResult.Metadata> results = new ArrayList<>();
+
+    blobs.forEach(
+        blob -> {
+          String name = blob.getName();
+          if (wildcardAsRegexp.matcher(name).matches() && !name.endsWith("/")) {
+            LOG.debug("Matched object: {}", name);
+
+            BlobProperties properties = blobContainerClient.getBlobClient(name).getProperties();
+            AzfsResourceId rid =
+                AzfsResourceId.fromComponents(account, container, name)
+                    .withSize(properties.getBlobSize())
+                    .withLastModified(Date.from(properties.getLastModified().toInstant()));
+
+            results.add(toMetadata(rid, properties.getContentEncoding()));
+          }
+        });
+
+    return MatchResult.create(MatchResult.Status.OK, results);
+  }
+
+  private MatchResult.Metadata toMetadata(AzfsResourceId path, String contentEncoding) {
+
+    checkArgument(path.getSize().isPresent(), "path has size");
+    boolean isReadSeekEfficient = !NON_READ_SEEK_EFFICIENT_ENCODINGS.contains(contentEncoding);
+
+    return MatchResult.Metadata.builder()
+        .setIsReadSeekEfficient(isReadSeekEfficient)
+        .setResourceId(path)
+        .setSizeBytes(path.getSize().get())
+        .setLastModifiedMillis(path.getLastModified().transform(Date::getTime).or(0L))
+        .build();
+  }
+
+  /**
+   * Returns {@link MatchResult MatchResults} for the given {@link AzfsResourceId paths}.
+   *
+   * <p>The number of returned {@link MatchResult MatchResults} equals to the number of given {@link
+   * AzfsResourceId paths}. Each {@link MatchResult} contains one {@link MatchResult.Metadata}.
+   */
+  @VisibleForTesting
+  private Iterable<MatchResult> matchNonGlobPaths(List<AzfsResourceId> paths) {
+    ImmutableList.Builder<MatchResult> toReturn = ImmutableList.builder();
+    for (AzfsResourceId path : paths) {
+      toReturn.add(toMatchResult(path));
+    }
+    return toReturn.build();
+  }
+
+  private MatchResult toMatchResult(AzfsResourceId path) {
+    BlobClient blobClient =
+        client.get().getBlobContainerClient(path.getContainer()).getBlobClient(path.getBlob());
+    BlobProperties blobProperties;
+
+    try {
+      blobProperties = blobClient.getProperties();
+    } catch (BlobStorageException e) {
+      if (e.getStatusCode() == 404) {
+        return MatchResult.create(MatchResult.Status.NOT_FOUND, new FileNotFoundException());
+      }
+      return MatchResult.create(MatchResult.Status.ERROR, new IOException(e));
+    }
+
+    return MatchResult.create(
+        MatchResult.Status.OK,
+        ImmutableList.of(
+            toMetadata(
+                path.withSize(blobProperties.getBlobSize())
+                    .withLastModified(Date.from(blobProperties.getLastModified().toInstant())),
+                blobProperties.getContentEncoding())));
   }
 
   @Override
   protected WritableByteChannel create(AzfsResourceId resourceId, CreateOptions createOptions)
       throws IOException {
-    // TODO
-    return null;
+    BlobContainerClient blobContainerClient =
+        client.get().getBlobContainerClient(resourceId.getContainer());
+    if (!blobContainerClient.exists()) {
+      throw new UnsupportedOperationException("create does not create containers.");
+    }
+
+    BlobClient blobClient = blobContainerClient.getBlobClient(resourceId.getBlob());
+    // The getBlobOutputStream method overwrites existing blobs,
+    // so throw an error in this case to prevent data loss
+    if (blobClient.exists()) {
+      throw new IOException("This filename is already in use.");
+    }
+
+    OutputStream outputStream;
+    try {
+      outputStream = blobClient.getBlockBlobClient().getBlobOutputStream();
+    } catch (BlobStorageException e) {
+      throw (IOException) e.getCause();
+    }
+    return newChannel(outputStream);
   }
 
   @Override
   protected ReadableByteChannel open(AzfsResourceId resourceId) throws IOException {
-    // TODO
-    return null;
+    BlobClient blobClient =
+        client
+            .get()
+            .getBlobContainerClient(resourceId.getContainer())
+            .getBlobClient(resourceId.getBlob());
+    if (!blobClient.exists()) {
+      throw new FileNotFoundException("The requested file doesn't exist.");
+    }
+    return new AzureReadableSeekableByteChannel(blobClient);
   }
 
   @Override
   protected void copy(List<AzfsResourceId> srcPaths, List<AzfsResourceId> destPaths)
       throws IOException {
-    // TODO
+    checkArgument(
+        srcPaths.size() == destPaths.size(),
+        "sizes of source paths and destination paths do not match");
+
+    Iterator<AzfsResourceId> sourcePathsIterator = srcPaths.iterator();
+    Iterator<AzfsResourceId> destinationPathsIterator = destPaths.iterator();
+    while (sourcePathsIterator.hasNext()) {
+      final AzfsResourceId sourcePath = sourcePathsIterator.next();
+      final AzfsResourceId destinationPath = destinationPathsIterator.next();
+      copy(sourcePath, destinationPath);
+    }
   }
 
   @VisibleForTesting
   void copy(AzfsResourceId sourcePath, AzfsResourceId destinationPath) throws IOException {
-    // TODO
+    checkArgument(
+        sourcePath.getBlob() != null && destinationPath.getBlob() != null,
+        "This method is intended to copy file-like resources, not directories.");
+
+    // get source blob client
+    BlobClient srcBlobClient =
+        client
+            .get()
+            .getBlobContainerClient(sourcePath.getContainer())
+            .getBlobClient(sourcePath.getBlob());
+    if (!srcBlobClient.exists()) {
+      throw new FileNotFoundException("The copy source does not exist.");
+    }
+
+    // get destination blob client
+    BlobContainerClient destBlobContainerClient =
+        client.get().getBlobContainerClient(destinationPath.getContainer());
+    if (!destBlobContainerClient.exists()) {
+      client.get().createBlobContainer(destinationPath.getContainer());
+    }
+    BlobClient destBlobClient = destBlobContainerClient.getBlobClient(destinationPath.getBlob());
+
+    destBlobClient.copyFromUrl(srcBlobClient.getBlobUrl() + generateSasToken());
+  }
+
+  @VisibleForTesting
+  String generateSasToken() throws IOException {
+    SharedAccessAccountPolicy sharedAccessAccountPolicy = new SharedAccessAccountPolicy();
+    long date = new Date().getTime();
+    long expiryDate = new Date(date + 8640000).getTime();
+
+    sharedAccessAccountPolicy.setPermissionsFromString("racwdlup");
+    sharedAccessAccountPolicy.setSharedAccessStartTime(new Date(date));
+    sharedAccessAccountPolicy.setSharedAccessExpiryTime(new Date(expiryDate));
+    sharedAccessAccountPolicy.setResourceTypeFromString(
+        "co"); // container, object, add s for service
+    sharedAccessAccountPolicy.setServiceFromString("b"); // blob, add "fqt" for file, queue, table
+
+    String storageConnectionString = options.getAzureConnectionString();
+    try {
+      CloudStorageAccount storageAccount = CloudStorageAccount.parse(storageConnectionString);
+      return "?" + storageAccount.generateSharedAccessSignature(sharedAccessAccountPolicy);
+    } catch (Exception e) {
+      throw (IOException) e.getCause();
+    }
   }
 
   @Override
   protected void rename(List<AzfsResourceId> srcResourceIds, List<AzfsResourceId> destResourceIds)
       throws IOException {
-    // TODO
+    copy(srcResourceIds, destResourceIds);
+    delete(srcResourceIds);
   }
 
+  // This method with delete a virtual folder or a blob

Review comment:
       Please make the comment as the javadoc.

##########
File path: sdks/java/io/azure/src/main/java/org/apache/beam/sdk/io/azure/blobstore/AzureBlobStoreFileSystem.java
##########
@@ -17,67 +17,438 @@
  */
 package org.apache.beam.sdk.io.azure.blobstore;
 
+import static java.nio.channels.Channels.newChannel;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkNotNull;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkState;
+
+import com.azure.core.http.rest.PagedIterable;
+import com.azure.storage.blob.BlobClient;
+import com.azure.storage.blob.BlobContainerClient;
+import com.azure.storage.blob.BlobServiceClient;
+import com.azure.storage.blob.BlobServiceClientBuilder;
+import com.azure.storage.blob.models.BlobItem;
+import com.azure.storage.blob.models.BlobProperties;
+import com.azure.storage.blob.models.BlobStorageException;
+import com.azure.storage.blob.models.ListBlobsOptions;
+import com.microsoft.azure.storage.CloudStorageAccount;
+import com.microsoft.azure.storage.SharedAccessAccountPolicy;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
+import java.time.Duration;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Date;
+import java.util.Iterator;
 import java.util.List;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 import org.apache.beam.sdk.io.FileSystem;
+import org.apache.beam.sdk.io.azure.options.BlobstoreClientBuilderFactory;
+import org.apache.beam.sdk.io.azure.options.BlobstoreOptions;
 import org.apache.beam.sdk.io.fs.CreateOptions;
 import org.apache.beam.sdk.io.fs.MatchResult;
+import org.apache.beam.sdk.util.InstanceBuilder;
 import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Supplier;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Suppliers;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.FluentIterable;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableSet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class AzureBlobStoreFileSystem extends FileSystem<AzfsResourceId> {
 
+  private static final Logger LOG = LoggerFactory.getLogger(AzureBlobStoreFileSystem.class);
+
+  private static final ImmutableSet<String> NON_READ_SEEK_EFFICIENT_ENCODINGS =
+      ImmutableSet.of("gzip");
+
+  private Supplier<BlobServiceClient> client;
+  private final BlobstoreOptions options;
+
+  AzureBlobStoreFileSystem(BlobstoreOptions options) {
+    this.options = checkNotNull(options, "options");
+
+    BlobServiceClientBuilder builder =
+        InstanceBuilder.ofType(BlobstoreClientBuilderFactory.class)
+            .fromClass(options.getBlobstoreClientFactoryClass())
+            .build()
+            .createBuilder(options);
+
+    // The Supplier is to make sure we don't call .build() unless we are actually using Azure.
+    client = Suppliers.memoize(builder::buildClient);
+  }
+
+  @VisibleForTesting
+  void setClient(BlobServiceClient client) {
+    this.client = Suppliers.ofInstance(client);
+  }
+
+  @VisibleForTesting
+  BlobServiceClient getClient() {
+    return client.get();
+  }
+
   @Override
   protected String getScheme() {
-    return "azfs";
+    return AzfsResourceId.SCHEME;
   }
 
   @Override
-  protected List<MatchResult> match(List<String> specs) throws IOException {
-    // TODO
-    return null;
+  protected List<MatchResult> match(List<String> specs) {
+    List<AzfsResourceId> paths =
+        specs.stream().map(AzfsResourceId::fromUri).collect(Collectors.toList());
+    List<AzfsResourceId> globs = new ArrayList<>();
+    List<AzfsResourceId> nonGlobs = new ArrayList<>();
+    List<Boolean> isGlobBooleans = new ArrayList<>();
+
+    for (AzfsResourceId path : paths) {
+      if (path.isWildcard()) {
+        globs.add(path);
+        isGlobBooleans.add(true);
+      } else {
+        nonGlobs.add(path);
+        isGlobBooleans.add(false);
+      }
+    }
+
+    Iterator<MatchResult> globMatches = matchGlobPaths(globs).iterator();
+    Iterator<MatchResult> nonGlobMatches = matchNonGlobPaths(nonGlobs).iterator();
+
+    ImmutableList.Builder<MatchResult> matchResults = ImmutableList.builder();
+    for (Boolean isGlob : isGlobBooleans) {
+      if (isGlob) {
+        checkState(globMatches.hasNext(), "Expect globMatches has next.");
+        matchResults.add(globMatches.next());
+      } else {
+        checkState(nonGlobMatches.hasNext(), "Expect nonGlobMatches has next.");
+        matchResults.add(nonGlobMatches.next());
+      }
+    }
+    checkState(!globMatches.hasNext(), "Expect no more elements in globMatches.");
+    checkState(!nonGlobMatches.hasNext(), "Expect no more elements in nonGlobMatches.");
+
+    return matchResults.build();
+  }
+
+  /**
+   * Expands glob expressions to regular expressions.
+   *
+   * @param globExp the glob expression to expand
+   * @return a string with the regular expression this glob expands to
+   */
+  @VisibleForTesting
+  static String wildcardToRegexp(String globExp) {
+    StringBuilder dst = new StringBuilder();
+    char[] src = globExp.replace("**/*", "**").toCharArray();
+    int i = 0;
+    while (i < src.length) {
+      char c = src[i++];
+      switch (c) {
+        case '*':
+          // One char lookahead for **
+          if (i < src.length && src[i] == '*') {
+            dst.append(".*");
+            ++i;
+          } else {
+            dst.append("[^/]*");
+          }
+          break;
+        case '?':
+          dst.append("[^/]");
+          break;
+        case '.':
+        case '+':
+        case '{':
+        case '}':
+        case '(':
+        case ')':
+        case '|':
+        case '^':
+        case '$':
+          // These need to be escaped in regular expressions
+          dst.append('\\').append(c);
+          break;
+        case '\\':
+          i = doubleSlashes(dst, src, i);
+          break;
+        default:
+          dst.append(c);
+          break;
+      }
+    }
+    return dst.toString();
+  }
+
+  private static int doubleSlashes(StringBuilder dst, char[] src, int i) {
+    // Emit the next character without special interpretation
+    dst.append("\\\\");
+    if ((i - 1) != src.length) {
+      dst.append(src[i]);
+      i++;
+    } else {
+      // A backslash at the very end is treated like an escaped backslash
+      dst.append('\\');
+    }
+    return i;
+  }
+
+  private List<MatchResult> matchGlobPaths(List<AzfsResourceId> globs) {
+    return FluentIterable.from(globs).transform(this::expand).toList();
+  }
+
+  /** Expands a pattern into {@link MatchResult}. */
+  @VisibleForTesting
+  MatchResult expand(AzfsResourceId azfsPattern) {
+
+    checkArgument(azfsPattern.isWildcard(), "is Wildcard");
+    String blobPrefix = azfsPattern.getBlobNonWildcardPrefix();
+    Pattern wildcardAsRegexp = Pattern.compile(wildcardToRegexp(azfsPattern.getBlob()));
+
+    LOG.debug(
+        "matching files in container {}, prefix {} against pattern {}",
+        azfsPattern.getContainer(),
+        blobPrefix,
+        wildcardAsRegexp.toString());
+
+    ListBlobsOptions listOptions = new ListBlobsOptions().setPrefix(blobPrefix);
+    Duration timeout = Duration.ZERO.plusMinutes(1);
+
+    String account = azfsPattern.getAccount();
+    String container = azfsPattern.getContainer();
+    BlobContainerClient blobContainerClient = client.get().getBlobContainerClient(container);
+    PagedIterable<BlobItem> blobs = blobContainerClient.listBlobs(listOptions, timeout);
+    List<MatchResult.Metadata> results = new ArrayList<>();
+
+    blobs.forEach(
+        blob -> {
+          String name = blob.getName();
+          if (wildcardAsRegexp.matcher(name).matches() && !name.endsWith("/")) {
+            LOG.debug("Matched object: {}", name);
+
+            BlobProperties properties = blobContainerClient.getBlobClient(name).getProperties();
+            AzfsResourceId rid =
+                AzfsResourceId.fromComponents(account, container, name)
+                    .withSize(properties.getBlobSize())
+                    .withLastModified(Date.from(properties.getLastModified().toInstant()));
+
+            results.add(toMetadata(rid, properties.getContentEncoding()));
+          }
+        });
+
+    return MatchResult.create(MatchResult.Status.OK, results);
+  }
+
+  private MatchResult.Metadata toMetadata(AzfsResourceId path, String contentEncoding) {
+
+    checkArgument(path.getSize().isPresent(), "path has size");
+    boolean isReadSeekEfficient = !NON_READ_SEEK_EFFICIENT_ENCODINGS.contains(contentEncoding);
+
+    return MatchResult.Metadata.builder()
+        .setIsReadSeekEfficient(isReadSeekEfficient)
+        .setResourceId(path)
+        .setSizeBytes(path.getSize().get())
+        .setLastModifiedMillis(path.getLastModified().transform(Date::getTime).or(0L))
+        .build();
+  }
+
+  /**
+   * Returns {@link MatchResult MatchResults} for the given {@link AzfsResourceId paths}.
+   *
+   * <p>The number of returned {@link MatchResult MatchResults} equals to the number of given {@link
+   * AzfsResourceId paths}. Each {@link MatchResult} contains one {@link MatchResult.Metadata}.
+   */
+  @VisibleForTesting
+  private Iterable<MatchResult> matchNonGlobPaths(List<AzfsResourceId> paths) {
+    ImmutableList.Builder<MatchResult> toReturn = ImmutableList.builder();
+    for (AzfsResourceId path : paths) {
+      toReturn.add(toMatchResult(path));
+    }
+    return toReturn.build();
+  }
+
+  private MatchResult toMatchResult(AzfsResourceId path) {
+    BlobClient blobClient =
+        client.get().getBlobContainerClient(path.getContainer()).getBlobClient(path.getBlob());
+    BlobProperties blobProperties;
+
+    try {
+      blobProperties = blobClient.getProperties();
+    } catch (BlobStorageException e) {
+      if (e.getStatusCode() == 404) {
+        return MatchResult.create(MatchResult.Status.NOT_FOUND, new FileNotFoundException());
+      }
+      return MatchResult.create(MatchResult.Status.ERROR, new IOException(e));
+    }
+
+    return MatchResult.create(
+        MatchResult.Status.OK,
+        ImmutableList.of(
+            toMetadata(
+                path.withSize(blobProperties.getBlobSize())
+                    .withLastModified(Date.from(blobProperties.getLastModified().toInstant())),
+                blobProperties.getContentEncoding())));
   }
 
   @Override
   protected WritableByteChannel create(AzfsResourceId resourceId, CreateOptions createOptions)
       throws IOException {
-    // TODO
-    return null;
+    BlobContainerClient blobContainerClient =
+        client.get().getBlobContainerClient(resourceId.getContainer());
+    if (!blobContainerClient.exists()) {
+      throw new UnsupportedOperationException("create does not create containers.");
+    }
+
+    BlobClient blobClient = blobContainerClient.getBlobClient(resourceId.getBlob());
+    // The getBlobOutputStream method overwrites existing blobs,
+    // so throw an error in this case to prevent data loss
+    if (blobClient.exists()) {
+      throw new IOException("This filename is already in use.");
+    }
+
+    OutputStream outputStream;
+    try {
+      outputStream = blobClient.getBlockBlobClient().getBlobOutputStream();
+    } catch (BlobStorageException e) {
+      throw (IOException) e.getCause();
+    }
+    return newChannel(outputStream);
   }
 
   @Override
   protected ReadableByteChannel open(AzfsResourceId resourceId) throws IOException {
-    // TODO
-    return null;
+    BlobClient blobClient =
+        client
+            .get()
+            .getBlobContainerClient(resourceId.getContainer())
+            .getBlobClient(resourceId.getBlob());
+    if (!blobClient.exists()) {
+      throw new FileNotFoundException("The requested file doesn't exist.");
+    }
+    return new AzureReadableSeekableByteChannel(blobClient);
   }
 
   @Override
   protected void copy(List<AzfsResourceId> srcPaths, List<AzfsResourceId> destPaths)
       throws IOException {
-    // TODO
+    checkArgument(
+        srcPaths.size() == destPaths.size(),
+        "sizes of source paths and destination paths do not match");
+
+    Iterator<AzfsResourceId> sourcePathsIterator = srcPaths.iterator();
+    Iterator<AzfsResourceId> destinationPathsIterator = destPaths.iterator();
+    while (sourcePathsIterator.hasNext()) {
+      final AzfsResourceId sourcePath = sourcePathsIterator.next();
+      final AzfsResourceId destinationPath = destinationPathsIterator.next();
+      copy(sourcePath, destinationPath);
+    }
   }
 
   @VisibleForTesting
   void copy(AzfsResourceId sourcePath, AzfsResourceId destinationPath) throws IOException {
-    // TODO
+    checkArgument(
+        sourcePath.getBlob() != null && destinationPath.getBlob() != null,
+        "This method is intended to copy file-like resources, not directories.");
+
+    // get source blob client
+    BlobClient srcBlobClient =
+        client
+            .get()
+            .getBlobContainerClient(sourcePath.getContainer())
+            .getBlobClient(sourcePath.getBlob());
+    if (!srcBlobClient.exists()) {
+      throw new FileNotFoundException("The copy source does not exist.");
+    }
+
+    // get destination blob client
+    BlobContainerClient destBlobContainerClient =
+        client.get().getBlobContainerClient(destinationPath.getContainer());
+    if (!destBlobContainerClient.exists()) {
+      client.get().createBlobContainer(destinationPath.getContainer());
+    }
+    BlobClient destBlobClient = destBlobContainerClient.getBlobClient(destinationPath.getBlob());
+
+    destBlobClient.copyFromUrl(srcBlobClient.getBlobUrl() + generateSasToken());
+  }
+
+  @VisibleForTesting
+  String generateSasToken() throws IOException {
+    SharedAccessAccountPolicy sharedAccessAccountPolicy = new SharedAccessAccountPolicy();
+    long date = new Date().getTime();
+    long expiryDate = new Date(date + 8640000).getTime();

Review comment:
       How do we pick up the number `8640000 ` here? If it should be a constant, we can make it as static final.

##########
File path: sdks/java/io/azure/src/main/java/org/apache/beam/sdk/io/azure/blobstore/AzureBlobStoreFileSystem.java
##########
@@ -17,67 +17,438 @@
  */
 package org.apache.beam.sdk.io.azure.blobstore;
 
+import static java.nio.channels.Channels.newChannel;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkNotNull;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkState;
+
+import com.azure.core.http.rest.PagedIterable;
+import com.azure.storage.blob.BlobClient;
+import com.azure.storage.blob.BlobContainerClient;
+import com.azure.storage.blob.BlobServiceClient;
+import com.azure.storage.blob.BlobServiceClientBuilder;
+import com.azure.storage.blob.models.BlobItem;
+import com.azure.storage.blob.models.BlobProperties;
+import com.azure.storage.blob.models.BlobStorageException;
+import com.azure.storage.blob.models.ListBlobsOptions;
+import com.microsoft.azure.storage.CloudStorageAccount;
+import com.microsoft.azure.storage.SharedAccessAccountPolicy;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
+import java.time.Duration;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Date;
+import java.util.Iterator;
 import java.util.List;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 import org.apache.beam.sdk.io.FileSystem;
+import org.apache.beam.sdk.io.azure.options.BlobstoreClientBuilderFactory;
+import org.apache.beam.sdk.io.azure.options.BlobstoreOptions;
 import org.apache.beam.sdk.io.fs.CreateOptions;
 import org.apache.beam.sdk.io.fs.MatchResult;
+import org.apache.beam.sdk.util.InstanceBuilder;
 import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Supplier;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Suppliers;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.FluentIterable;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableSet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class AzureBlobStoreFileSystem extends FileSystem<AzfsResourceId> {
 
+  private static final Logger LOG = LoggerFactory.getLogger(AzureBlobStoreFileSystem.class);
+
+  private static final ImmutableSet<String> NON_READ_SEEK_EFFICIENT_ENCODINGS =
+      ImmutableSet.of("gzip");
+
+  private Supplier<BlobServiceClient> client;
+  private final BlobstoreOptions options;
+
+  AzureBlobStoreFileSystem(BlobstoreOptions options) {
+    this.options = checkNotNull(options, "options");
+
+    BlobServiceClientBuilder builder =
+        InstanceBuilder.ofType(BlobstoreClientBuilderFactory.class)
+            .fromClass(options.getBlobstoreClientFactoryClass())
+            .build()
+            .createBuilder(options);
+
+    // The Supplier is to make sure we don't call .build() unless we are actually using Azure.
+    client = Suppliers.memoize(builder::buildClient);
+  }
+
+  @VisibleForTesting
+  void setClient(BlobServiceClient client) {
+    this.client = Suppliers.ofInstance(client);
+  }
+
+  @VisibleForTesting
+  BlobServiceClient getClient() {
+    return client.get();
+  }
+
   @Override
   protected String getScheme() {
-    return "azfs";
+    return AzfsResourceId.SCHEME;
   }
 
   @Override
-  protected List<MatchResult> match(List<String> specs) throws IOException {
-    // TODO
-    return null;
+  protected List<MatchResult> match(List<String> specs) {
+    List<AzfsResourceId> paths =
+        specs.stream().map(AzfsResourceId::fromUri).collect(Collectors.toList());
+    List<AzfsResourceId> globs = new ArrayList<>();
+    List<AzfsResourceId> nonGlobs = new ArrayList<>();
+    List<Boolean> isGlobBooleans = new ArrayList<>();
+
+    for (AzfsResourceId path : paths) {
+      if (path.isWildcard()) {
+        globs.add(path);
+        isGlobBooleans.add(true);
+      } else {
+        nonGlobs.add(path);
+        isGlobBooleans.add(false);
+      }
+    }
+
+    Iterator<MatchResult> globMatches = matchGlobPaths(globs).iterator();
+    Iterator<MatchResult> nonGlobMatches = matchNonGlobPaths(nonGlobs).iterator();
+
+    ImmutableList.Builder<MatchResult> matchResults = ImmutableList.builder();
+    for (Boolean isGlob : isGlobBooleans) {
+      if (isGlob) {
+        checkState(globMatches.hasNext(), "Expect globMatches has next.");
+        matchResults.add(globMatches.next());
+      } else {
+        checkState(nonGlobMatches.hasNext(), "Expect nonGlobMatches has next.");
+        matchResults.add(nonGlobMatches.next());
+      }
+    }
+    checkState(!globMatches.hasNext(), "Expect no more elements in globMatches.");
+    checkState(!nonGlobMatches.hasNext(), "Expect no more elements in nonGlobMatches.");
+
+    return matchResults.build();
+  }
+
+  /**
+   * Expands glob expressions to regular expressions.
+   *
+   * @param globExp the glob expression to expand
+   * @return a string with the regular expression this glob expands to
+   */
+  @VisibleForTesting
+  static String wildcardToRegexp(String globExp) {
+    StringBuilder dst = new StringBuilder();
+    char[] src = globExp.replace("**/*", "**").toCharArray();
+    int i = 0;
+    while (i < src.length) {
+      char c = src[i++];
+      switch (c) {
+        case '*':
+          // One char lookahead for **
+          if (i < src.length && src[i] == '*') {
+            dst.append(".*");
+            ++i;
+          } else {
+            dst.append("[^/]*");
+          }
+          break;
+        case '?':
+          dst.append("[^/]");
+          break;
+        case '.':
+        case '+':
+        case '{':
+        case '}':
+        case '(':
+        case ')':
+        case '|':
+        case '^':
+        case '$':
+          // These need to be escaped in regular expressions
+          dst.append('\\').append(c);
+          break;
+        case '\\':
+          i = doubleSlashes(dst, src, i);
+          break;
+        default:
+          dst.append(c);
+          break;
+      }
+    }
+    return dst.toString();
+  }
+
+  private static int doubleSlashes(StringBuilder dst, char[] src, int i) {
+    // Emit the next character without special interpretation
+    dst.append("\\\\");
+    if ((i - 1) != src.length) {
+      dst.append(src[i]);
+      i++;
+    } else {
+      // A backslash at the very end is treated like an escaped backslash
+      dst.append('\\');
+    }
+    return i;
+  }
+
+  private List<MatchResult> matchGlobPaths(List<AzfsResourceId> globs) {
+    return FluentIterable.from(globs).transform(this::expand).toList();
+  }
+
+  /** Expands a pattern into {@link MatchResult}. */
+  @VisibleForTesting
+  MatchResult expand(AzfsResourceId azfsPattern) {
+
+    checkArgument(azfsPattern.isWildcard(), "is Wildcard");
+    String blobPrefix = azfsPattern.getBlobNonWildcardPrefix();
+    Pattern wildcardAsRegexp = Pattern.compile(wildcardToRegexp(azfsPattern.getBlob()));
+
+    LOG.debug(
+        "matching files in container {}, prefix {} against pattern {}",
+        azfsPattern.getContainer(),
+        blobPrefix,
+        wildcardAsRegexp.toString());
+
+    ListBlobsOptions listOptions = new ListBlobsOptions().setPrefix(blobPrefix);
+    Duration timeout = Duration.ZERO.plusMinutes(1);
+
+    String account = azfsPattern.getAccount();
+    String container = azfsPattern.getContainer();
+    BlobContainerClient blobContainerClient = client.get().getBlobContainerClient(container);
+    PagedIterable<BlobItem> blobs = blobContainerClient.listBlobs(listOptions, timeout);
+    List<MatchResult.Metadata> results = new ArrayList<>();
+
+    blobs.forEach(
+        blob -> {
+          String name = blob.getName();
+          if (wildcardAsRegexp.matcher(name).matches() && !name.endsWith("/")) {
+            LOG.debug("Matched object: {}", name);
+
+            BlobProperties properties = blobContainerClient.getBlobClient(name).getProperties();
+            AzfsResourceId rid =
+                AzfsResourceId.fromComponents(account, container, name)
+                    .withSize(properties.getBlobSize())
+                    .withLastModified(Date.from(properties.getLastModified().toInstant()));
+
+            results.add(toMetadata(rid, properties.getContentEncoding()));
+          }
+        });
+
+    return MatchResult.create(MatchResult.Status.OK, results);
+  }
+
+  private MatchResult.Metadata toMetadata(AzfsResourceId path, String contentEncoding) {
+
+    checkArgument(path.getSize().isPresent(), "path has size");

Review comment:
       Please make the error message specific.

##########
File path: sdks/java/io/azure/src/main/java/org/apache/beam/sdk/io/azure/blobstore/AzureBlobStoreFileSystem.java
##########
@@ -17,67 +17,438 @@
  */
 package org.apache.beam.sdk.io.azure.blobstore;
 
+import static java.nio.channels.Channels.newChannel;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkNotNull;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkState;
+
+import com.azure.core.http.rest.PagedIterable;
+import com.azure.storage.blob.BlobClient;
+import com.azure.storage.blob.BlobContainerClient;
+import com.azure.storage.blob.BlobServiceClient;
+import com.azure.storage.blob.BlobServiceClientBuilder;
+import com.azure.storage.blob.models.BlobItem;
+import com.azure.storage.blob.models.BlobProperties;
+import com.azure.storage.blob.models.BlobStorageException;
+import com.azure.storage.blob.models.ListBlobsOptions;
+import com.microsoft.azure.storage.CloudStorageAccount;
+import com.microsoft.azure.storage.SharedAccessAccountPolicy;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
+import java.time.Duration;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Date;
+import java.util.Iterator;
 import java.util.List;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 import org.apache.beam.sdk.io.FileSystem;
+import org.apache.beam.sdk.io.azure.options.BlobstoreClientBuilderFactory;
+import org.apache.beam.sdk.io.azure.options.BlobstoreOptions;
 import org.apache.beam.sdk.io.fs.CreateOptions;
 import org.apache.beam.sdk.io.fs.MatchResult;
+import org.apache.beam.sdk.util.InstanceBuilder;
 import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Supplier;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Suppliers;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.FluentIterable;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableSet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class AzureBlobStoreFileSystem extends FileSystem<AzfsResourceId> {
 
+  private static final Logger LOG = LoggerFactory.getLogger(AzureBlobStoreFileSystem.class);
+
+  private static final ImmutableSet<String> NON_READ_SEEK_EFFICIENT_ENCODINGS =
+      ImmutableSet.of("gzip");
+
+  private Supplier<BlobServiceClient> client;
+  private final BlobstoreOptions options;
+
+  AzureBlobStoreFileSystem(BlobstoreOptions options) {
+    this.options = checkNotNull(options, "options");
+
+    BlobServiceClientBuilder builder =
+        InstanceBuilder.ofType(BlobstoreClientBuilderFactory.class)
+            .fromClass(options.getBlobstoreClientFactoryClass())
+            .build()
+            .createBuilder(options);
+
+    // The Supplier is to make sure we don't call .build() unless we are actually using Azure.
+    client = Suppliers.memoize(builder::buildClient);
+  }
+
+  @VisibleForTesting
+  void setClient(BlobServiceClient client) {
+    this.client = Suppliers.ofInstance(client);
+  }
+
+  @VisibleForTesting
+  BlobServiceClient getClient() {
+    return client.get();
+  }
+
   @Override
   protected String getScheme() {
-    return "azfs";
+    return AzfsResourceId.SCHEME;
   }
 
   @Override
-  protected List<MatchResult> match(List<String> specs) throws IOException {
-    // TODO
-    return null;
+  protected List<MatchResult> match(List<String> specs) {
+    List<AzfsResourceId> paths =
+        specs.stream().map(AzfsResourceId::fromUri).collect(Collectors.toList());
+    List<AzfsResourceId> globs = new ArrayList<>();
+    List<AzfsResourceId> nonGlobs = new ArrayList<>();
+    List<Boolean> isGlobBooleans = new ArrayList<>();
+
+    for (AzfsResourceId path : paths) {
+      if (path.isWildcard()) {
+        globs.add(path);
+        isGlobBooleans.add(true);
+      } else {
+        nonGlobs.add(path);
+        isGlobBooleans.add(false);
+      }
+    }
+
+    Iterator<MatchResult> globMatches = matchGlobPaths(globs).iterator();
+    Iterator<MatchResult> nonGlobMatches = matchNonGlobPaths(nonGlobs).iterator();
+
+    ImmutableList.Builder<MatchResult> matchResults = ImmutableList.builder();
+    for (Boolean isGlob : isGlobBooleans) {
+      if (isGlob) {
+        checkState(globMatches.hasNext(), "Expect globMatches has next.");
+        matchResults.add(globMatches.next());
+      } else {
+        checkState(nonGlobMatches.hasNext(), "Expect nonGlobMatches has next.");
+        matchResults.add(nonGlobMatches.next());
+      }
+    }
+    checkState(!globMatches.hasNext(), "Expect no more elements in globMatches.");
+    checkState(!nonGlobMatches.hasNext(), "Expect no more elements in nonGlobMatches.");
+
+    return matchResults.build();
+  }
+
+  /**
+   * Expands glob expressions to regular expressions.
+   *
+   * @param globExp the glob expression to expand
+   * @return a string with the regular expression this glob expands to
+   */
+  @VisibleForTesting
+  static String wildcardToRegexp(String globExp) {
+    StringBuilder dst = new StringBuilder();
+    char[] src = globExp.replace("**/*", "**").toCharArray();
+    int i = 0;
+    while (i < src.length) {
+      char c = src[i++];
+      switch (c) {
+        case '*':
+          // One char lookahead for **
+          if (i < src.length && src[i] == '*') {
+            dst.append(".*");
+            ++i;
+          } else {
+            dst.append("[^/]*");
+          }
+          break;
+        case '?':
+          dst.append("[^/]");
+          break;
+        case '.':
+        case '+':
+        case '{':
+        case '}':
+        case '(':
+        case ')':
+        case '|':
+        case '^':
+        case '$':
+          // These need to be escaped in regular expressions
+          dst.append('\\').append(c);
+          break;
+        case '\\':
+          i = doubleSlashes(dst, src, i);
+          break;
+        default:
+          dst.append(c);
+          break;
+      }
+    }
+    return dst.toString();
+  }
+
+  private static int doubleSlashes(StringBuilder dst, char[] src, int i) {
+    // Emit the next character without special interpretation
+    dst.append("\\\\");
+    if ((i - 1) != src.length) {
+      dst.append(src[i]);
+      i++;
+    } else {
+      // A backslash at the very end is treated like an escaped backslash
+      dst.append('\\');
+    }
+    return i;
+  }
+
+  private List<MatchResult> matchGlobPaths(List<AzfsResourceId> globs) {
+    return FluentIterable.from(globs).transform(this::expand).toList();
+  }
+
+  /** Expands a pattern into {@link MatchResult}. */
+  @VisibleForTesting
+  MatchResult expand(AzfsResourceId azfsPattern) {
+
+    checkArgument(azfsPattern.isWildcard(), "is Wildcard");
+    String blobPrefix = azfsPattern.getBlobNonWildcardPrefix();
+    Pattern wildcardAsRegexp = Pattern.compile(wildcardToRegexp(azfsPattern.getBlob()));
+
+    LOG.debug(
+        "matching files in container {}, prefix {} against pattern {}",
+        azfsPattern.getContainer(),
+        blobPrefix,
+        wildcardAsRegexp.toString());
+
+    ListBlobsOptions listOptions = new ListBlobsOptions().setPrefix(blobPrefix);
+    Duration timeout = Duration.ZERO.plusMinutes(1);

Review comment:
       `Duration.ofMinutes(1)`

##########
File path: sdks/java/io/azure/src/test/java/org/apache/beam/sdk/io/azure/blobstore/AzfsTestUtils.java
##########
@@ -0,0 +1,42 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.beam.sdk.io.azure.blobstore;
+
+import com.azure.storage.blob.BlobServiceClient;
+import org.apache.beam.sdk.io.azure.options.BlobstoreOptions;
+import org.apache.beam.sdk.options.PipelineOptionsFactory;
+import org.mockito.Mockito;
+
+class AzfsTestUtils {
+  static BlobstoreOptions azfsOptions() {
+    BlobstoreOptions options = PipelineOptionsFactory.as(BlobstoreOptions.class);
+    options.setAzureConnectionString(System.getenv("AZURE_STORAGE_CONNECTION_STRING"));

Review comment:
       It assumes that the running env has `AZURE_STORAGE_CONNECTION_STRING`, which should be false for most of time. 

##########
File path: sdks/java/io/azure/src/main/java/org/apache/beam/sdk/io/azure/options/AzureOptions.java
##########
@@ -0,0 +1,86 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.beam.sdk.io.azure.options;
+
+import com.azure.core.credential.TokenCredential;
+import com.azure.core.util.Configuration;
+import com.azure.identity.DefaultAzureCredentialBuilder;
+import org.apache.beam.sdk.options.Default;
+import org.apache.beam.sdk.options.DefaultValueFactory;
+import org.apache.beam.sdk.options.Description;
+import org.apache.beam.sdk.options.PipelineOptions;
+
+public interface AzureOptions extends PipelineOptions {
+
+  // TODO: Add any other azure options that users should be able to configure
+  // TODO: Confirm that Azure options are in this file, Blobstore options in BlobstoreOptions

Review comment:
       It seems like you have already separated the Azure options and Blob options.

##########
File path: sdks/java/io/azure/src/main/java/org/apache/beam/sdk/io/azure/blobstore/AzureBlobStoreFileSystem.java
##########
@@ -17,67 +17,438 @@
  */
 package org.apache.beam.sdk.io.azure.blobstore;
 
+import static java.nio.channels.Channels.newChannel;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkNotNull;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkState;
+
+import com.azure.core.http.rest.PagedIterable;
+import com.azure.storage.blob.BlobClient;
+import com.azure.storage.blob.BlobContainerClient;
+import com.azure.storage.blob.BlobServiceClient;
+import com.azure.storage.blob.BlobServiceClientBuilder;
+import com.azure.storage.blob.models.BlobItem;
+import com.azure.storage.blob.models.BlobProperties;
+import com.azure.storage.blob.models.BlobStorageException;
+import com.azure.storage.blob.models.ListBlobsOptions;
+import com.microsoft.azure.storage.CloudStorageAccount;
+import com.microsoft.azure.storage.SharedAccessAccountPolicy;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
+import java.time.Duration;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Date;
+import java.util.Iterator;
 import java.util.List;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 import org.apache.beam.sdk.io.FileSystem;
+import org.apache.beam.sdk.io.azure.options.BlobstoreClientBuilderFactory;
+import org.apache.beam.sdk.io.azure.options.BlobstoreOptions;
 import org.apache.beam.sdk.io.fs.CreateOptions;
 import org.apache.beam.sdk.io.fs.MatchResult;
+import org.apache.beam.sdk.util.InstanceBuilder;
 import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Supplier;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Suppliers;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.FluentIterable;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableSet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class AzureBlobStoreFileSystem extends FileSystem<AzfsResourceId> {
 
+  private static final Logger LOG = LoggerFactory.getLogger(AzureBlobStoreFileSystem.class);
+
+  private static final ImmutableSet<String> NON_READ_SEEK_EFFICIENT_ENCODINGS =
+      ImmutableSet.of("gzip");
+
+  private Supplier<BlobServiceClient> client;
+  private final BlobstoreOptions options;
+
+  AzureBlobStoreFileSystem(BlobstoreOptions options) {
+    this.options = checkNotNull(options, "options");
+
+    BlobServiceClientBuilder builder =
+        InstanceBuilder.ofType(BlobstoreClientBuilderFactory.class)
+            .fromClass(options.getBlobstoreClientFactoryClass())
+            .build()
+            .createBuilder(options);
+
+    // The Supplier is to make sure we don't call .build() unless we are actually using Azure.
+    client = Suppliers.memoize(builder::buildClient);
+  }
+
+  @VisibleForTesting
+  void setClient(BlobServiceClient client) {
+    this.client = Suppliers.ofInstance(client);
+  }
+
+  @VisibleForTesting
+  BlobServiceClient getClient() {
+    return client.get();
+  }
+
   @Override
   protected String getScheme() {
-    return "azfs";
+    return AzfsResourceId.SCHEME;
   }
 
   @Override
-  protected List<MatchResult> match(List<String> specs) throws IOException {
-    // TODO
-    return null;
+  protected List<MatchResult> match(List<String> specs) {
+    List<AzfsResourceId> paths =
+        specs.stream().map(AzfsResourceId::fromUri).collect(Collectors.toList());
+    List<AzfsResourceId> globs = new ArrayList<>();
+    List<AzfsResourceId> nonGlobs = new ArrayList<>();
+    List<Boolean> isGlobBooleans = new ArrayList<>();
+
+    for (AzfsResourceId path : paths) {
+      if (path.isWildcard()) {
+        globs.add(path);
+        isGlobBooleans.add(true);
+      } else {
+        nonGlobs.add(path);
+        isGlobBooleans.add(false);
+      }
+    }
+
+    Iterator<MatchResult> globMatches = matchGlobPaths(globs).iterator();
+    Iterator<MatchResult> nonGlobMatches = matchNonGlobPaths(nonGlobs).iterator();
+
+    ImmutableList.Builder<MatchResult> matchResults = ImmutableList.builder();
+    for (Boolean isGlob : isGlobBooleans) {
+      if (isGlob) {
+        checkState(globMatches.hasNext(), "Expect globMatches has next.");
+        matchResults.add(globMatches.next());
+      } else {
+        checkState(nonGlobMatches.hasNext(), "Expect nonGlobMatches has next.");
+        matchResults.add(nonGlobMatches.next());
+      }
+    }
+    checkState(!globMatches.hasNext(), "Expect no more elements in globMatches.");
+    checkState(!nonGlobMatches.hasNext(), "Expect no more elements in nonGlobMatches.");
+
+    return matchResults.build();
+  }
+
+  /**
+   * Expands glob expressions to regular expressions.
+   *
+   * @param globExp the glob expression to expand
+   * @return a string with the regular expression this glob expands to
+   */
+  @VisibleForTesting
+  static String wildcardToRegexp(String globExp) {
+    StringBuilder dst = new StringBuilder();
+    char[] src = globExp.replace("**/*", "**").toCharArray();
+    int i = 0;
+    while (i < src.length) {
+      char c = src[i++];
+      switch (c) {
+        case '*':
+          // One char lookahead for **
+          if (i < src.length && src[i] == '*') {
+            dst.append(".*");
+            ++i;
+          } else {
+            dst.append("[^/]*");
+          }
+          break;
+        case '?':
+          dst.append("[^/]");
+          break;
+        case '.':
+        case '+':
+        case '{':
+        case '}':
+        case '(':
+        case ')':
+        case '|':
+        case '^':
+        case '$':
+          // These need to be escaped in regular expressions
+          dst.append('\\').append(c);
+          break;
+        case '\\':
+          i = doubleSlashes(dst, src, i);
+          break;
+        default:
+          dst.append(c);
+          break;
+      }
+    }
+    return dst.toString();
+  }
+
+  private static int doubleSlashes(StringBuilder dst, char[] src, int i) {
+    // Emit the next character without special interpretation
+    dst.append("\\\\");
+    if ((i - 1) != src.length) {
+      dst.append(src[i]);
+      i++;
+    } else {
+      // A backslash at the very end is treated like an escaped backslash
+      dst.append('\\');
+    }
+    return i;
+  }
+
+  private List<MatchResult> matchGlobPaths(List<AzfsResourceId> globs) {
+    return FluentIterable.from(globs).transform(this::expand).toList();
+  }
+
+  /** Expands a pattern into {@link MatchResult}. */
+  @VisibleForTesting
+  MatchResult expand(AzfsResourceId azfsPattern) {
+
+    checkArgument(azfsPattern.isWildcard(), "is Wildcard");
+    String blobPrefix = azfsPattern.getBlobNonWildcardPrefix();
+    Pattern wildcardAsRegexp = Pattern.compile(wildcardToRegexp(azfsPattern.getBlob()));
+
+    LOG.debug(
+        "matching files in container {}, prefix {} against pattern {}",
+        azfsPattern.getContainer(),
+        blobPrefix,
+        wildcardAsRegexp.toString());
+
+    ListBlobsOptions listOptions = new ListBlobsOptions().setPrefix(blobPrefix);
+    Duration timeout = Duration.ZERO.plusMinutes(1);
+
+    String account = azfsPattern.getAccount();
+    String container = azfsPattern.getContainer();
+    BlobContainerClient blobContainerClient = client.get().getBlobContainerClient(container);
+    PagedIterable<BlobItem> blobs = blobContainerClient.listBlobs(listOptions, timeout);
+    List<MatchResult.Metadata> results = new ArrayList<>();
+
+    blobs.forEach(
+        blob -> {
+          String name = blob.getName();
+          if (wildcardAsRegexp.matcher(name).matches() && !name.endsWith("/")) {
+            LOG.debug("Matched object: {}", name);
+
+            BlobProperties properties = blobContainerClient.getBlobClient(name).getProperties();
+            AzfsResourceId rid =
+                AzfsResourceId.fromComponents(account, container, name)
+                    .withSize(properties.getBlobSize())
+                    .withLastModified(Date.from(properties.getLastModified().toInstant()));
+
+            results.add(toMetadata(rid, properties.getContentEncoding()));
+          }
+        });
+
+    return MatchResult.create(MatchResult.Status.OK, results);
+  }
+
+  private MatchResult.Metadata toMetadata(AzfsResourceId path, String contentEncoding) {
+
+    checkArgument(path.getSize().isPresent(), "path has size");
+    boolean isReadSeekEfficient = !NON_READ_SEEK_EFFICIENT_ENCODINGS.contains(contentEncoding);
+
+    return MatchResult.Metadata.builder()
+        .setIsReadSeekEfficient(isReadSeekEfficient)
+        .setResourceId(path)
+        .setSizeBytes(path.getSize().get())
+        .setLastModifiedMillis(path.getLastModified().transform(Date::getTime).or(0L))
+        .build();
+  }
+
+  /**
+   * Returns {@link MatchResult MatchResults} for the given {@link AzfsResourceId paths}.
+   *
+   * <p>The number of returned {@link MatchResult MatchResults} equals to the number of given {@link
+   * AzfsResourceId paths}. Each {@link MatchResult} contains one {@link MatchResult.Metadata}.
+   */
+  @VisibleForTesting
+  private Iterable<MatchResult> matchNonGlobPaths(List<AzfsResourceId> paths) {
+    ImmutableList.Builder<MatchResult> toReturn = ImmutableList.builder();
+    for (AzfsResourceId path : paths) {
+      toReturn.add(toMatchResult(path));
+    }
+    return toReturn.build();
+  }
+
+  private MatchResult toMatchResult(AzfsResourceId path) {
+    BlobClient blobClient =
+        client.get().getBlobContainerClient(path.getContainer()).getBlobClient(path.getBlob());
+    BlobProperties blobProperties;
+
+    try {
+      blobProperties = blobClient.getProperties();
+    } catch (BlobStorageException e) {
+      if (e.getStatusCode() == 404) {
+        return MatchResult.create(MatchResult.Status.NOT_FOUND, new FileNotFoundException());
+      }
+      return MatchResult.create(MatchResult.Status.ERROR, new IOException(e));
+    }
+
+    return MatchResult.create(
+        MatchResult.Status.OK,
+        ImmutableList.of(
+            toMetadata(
+                path.withSize(blobProperties.getBlobSize())
+                    .withLastModified(Date.from(blobProperties.getLastModified().toInstant())),
+                blobProperties.getContentEncoding())));
   }
 
   @Override
   protected WritableByteChannel create(AzfsResourceId resourceId, CreateOptions createOptions)
       throws IOException {
-    // TODO
-    return null;
+    BlobContainerClient blobContainerClient =
+        client.get().getBlobContainerClient(resourceId.getContainer());
+    if (!blobContainerClient.exists()) {
+      throw new UnsupportedOperationException("create does not create containers.");
+    }
+
+    BlobClient blobClient = blobContainerClient.getBlobClient(resourceId.getBlob());
+    // The getBlobOutputStream method overwrites existing blobs,
+    // so throw an error in this case to prevent data loss
+    if (blobClient.exists()) {
+      throw new IOException("This filename is already in use.");
+    }
+
+    OutputStream outputStream;
+    try {
+      outputStream = blobClient.getBlockBlobClient().getBlobOutputStream();
+    } catch (BlobStorageException e) {
+      throw (IOException) e.getCause();
+    }
+    return newChannel(outputStream);
   }
 
   @Override
   protected ReadableByteChannel open(AzfsResourceId resourceId) throws IOException {
-    // TODO
-    return null;
+    BlobClient blobClient =
+        client
+            .get()
+            .getBlobContainerClient(resourceId.getContainer())
+            .getBlobClient(resourceId.getBlob());
+    if (!blobClient.exists()) {
+      throw new FileNotFoundException("The requested file doesn't exist.");
+    }
+    return new AzureReadableSeekableByteChannel(blobClient);
   }
 
   @Override
   protected void copy(List<AzfsResourceId> srcPaths, List<AzfsResourceId> destPaths)
       throws IOException {
-    // TODO
+    checkArgument(
+        srcPaths.size() == destPaths.size(),
+        "sizes of source paths and destination paths do not match");
+
+    Iterator<AzfsResourceId> sourcePathsIterator = srcPaths.iterator();
+    Iterator<AzfsResourceId> destinationPathsIterator = destPaths.iterator();
+    while (sourcePathsIterator.hasNext()) {
+      final AzfsResourceId sourcePath = sourcePathsIterator.next();
+      final AzfsResourceId destinationPath = destinationPathsIterator.next();
+      copy(sourcePath, destinationPath);
+    }
   }
 
   @VisibleForTesting
   void copy(AzfsResourceId sourcePath, AzfsResourceId destinationPath) throws IOException {
-    // TODO
+    checkArgument(
+        sourcePath.getBlob() != null && destinationPath.getBlob() != null,
+        "This method is intended to copy file-like resources, not directories.");
+
+    // get source blob client
+    BlobClient srcBlobClient =
+        client
+            .get()
+            .getBlobContainerClient(sourcePath.getContainer())
+            .getBlobClient(sourcePath.getBlob());
+    if (!srcBlobClient.exists()) {
+      throw new FileNotFoundException("The copy source does not exist.");
+    }
+
+    // get destination blob client
+    BlobContainerClient destBlobContainerClient =
+        client.get().getBlobContainerClient(destinationPath.getContainer());
+    if (!destBlobContainerClient.exists()) {
+      client.get().createBlobContainer(destinationPath.getContainer());
+    }
+    BlobClient destBlobClient = destBlobContainerClient.getBlobClient(destinationPath.getBlob());
+
+    destBlobClient.copyFromUrl(srcBlobClient.getBlobUrl() + generateSasToken());
+  }
+
+  @VisibleForTesting
+  String generateSasToken() throws IOException {
+    SharedAccessAccountPolicy sharedAccessAccountPolicy = new SharedAccessAccountPolicy();
+    long date = new Date().getTime();
+    long expiryDate = new Date(date + 8640000).getTime();
+
+    sharedAccessAccountPolicy.setPermissionsFromString("racwdlup");

Review comment:
       Can we make the constant string `racwdlup ` and `co ` as static final attribute of the class?

##########
File path: sdks/java/io/azure/src/main/java/org/apache/beam/sdk/io/azure/blobstore/AzureBlobStoreFileSystem.java
##########
@@ -17,67 +17,438 @@
  */
 package org.apache.beam.sdk.io.azure.blobstore;
 
+import static java.nio.channels.Channels.newChannel;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkArgument;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkNotNull;
+import static org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Preconditions.checkState;
+
+import com.azure.core.http.rest.PagedIterable;
+import com.azure.storage.blob.BlobClient;
+import com.azure.storage.blob.BlobContainerClient;
+import com.azure.storage.blob.BlobServiceClient;
+import com.azure.storage.blob.BlobServiceClientBuilder;
+import com.azure.storage.blob.models.BlobItem;
+import com.azure.storage.blob.models.BlobProperties;
+import com.azure.storage.blob.models.BlobStorageException;
+import com.azure.storage.blob.models.ListBlobsOptions;
+import com.microsoft.azure.storage.CloudStorageAccount;
+import com.microsoft.azure.storage.SharedAccessAccountPolicy;
+import java.io.FileNotFoundException;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.channels.WritableByteChannel;
+import java.time.Duration;
+import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Date;
+import java.util.Iterator;
 import java.util.List;
+import java.util.regex.Pattern;
+import java.util.stream.Collectors;
 import org.apache.beam.sdk.io.FileSystem;
+import org.apache.beam.sdk.io.azure.options.BlobstoreClientBuilderFactory;
+import org.apache.beam.sdk.io.azure.options.BlobstoreOptions;
 import org.apache.beam.sdk.io.fs.CreateOptions;
 import org.apache.beam.sdk.io.fs.MatchResult;
+import org.apache.beam.sdk.util.InstanceBuilder;
 import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.annotations.VisibleForTesting;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Supplier;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.base.Suppliers;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.FluentIterable;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableList;
+import org.apache.beam.vendor.guava.v26_0_jre.com.google.common.collect.ImmutableSet;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 class AzureBlobStoreFileSystem extends FileSystem<AzfsResourceId> {
 
+  private static final Logger LOG = LoggerFactory.getLogger(AzureBlobStoreFileSystem.class);
+
+  private static final ImmutableSet<String> NON_READ_SEEK_EFFICIENT_ENCODINGS =
+      ImmutableSet.of("gzip");
+
+  private Supplier<BlobServiceClient> client;
+  private final BlobstoreOptions options;
+
+  AzureBlobStoreFileSystem(BlobstoreOptions options) {
+    this.options = checkNotNull(options, "options");
+
+    BlobServiceClientBuilder builder =
+        InstanceBuilder.ofType(BlobstoreClientBuilderFactory.class)
+            .fromClass(options.getBlobstoreClientFactoryClass())
+            .build()
+            .createBuilder(options);
+
+    // The Supplier is to make sure we don't call .build() unless we are actually using Azure.
+    client = Suppliers.memoize(builder::buildClient);
+  }
+
+  @VisibleForTesting
+  void setClient(BlobServiceClient client) {
+    this.client = Suppliers.ofInstance(client);
+  }
+
+  @VisibleForTesting
+  BlobServiceClient getClient() {
+    return client.get();
+  }
+
   @Override
   protected String getScheme() {
-    return "azfs";
+    return AzfsResourceId.SCHEME;
   }
 
   @Override
-  protected List<MatchResult> match(List<String> specs) throws IOException {
-    // TODO
-    return null;
+  protected List<MatchResult> match(List<String> specs) {
+    List<AzfsResourceId> paths =
+        specs.stream().map(AzfsResourceId::fromUri).collect(Collectors.toList());
+    List<AzfsResourceId> globs = new ArrayList<>();
+    List<AzfsResourceId> nonGlobs = new ArrayList<>();
+    List<Boolean> isGlobBooleans = new ArrayList<>();
+
+    for (AzfsResourceId path : paths) {
+      if (path.isWildcard()) {
+        globs.add(path);
+        isGlobBooleans.add(true);
+      } else {
+        nonGlobs.add(path);
+        isGlobBooleans.add(false);
+      }
+    }
+
+    Iterator<MatchResult> globMatches = matchGlobPaths(globs).iterator();
+    Iterator<MatchResult> nonGlobMatches = matchNonGlobPaths(nonGlobs).iterator();
+
+    ImmutableList.Builder<MatchResult> matchResults = ImmutableList.builder();
+    for (Boolean isGlob : isGlobBooleans) {
+      if (isGlob) {
+        checkState(globMatches.hasNext(), "Expect globMatches has next.");
+        matchResults.add(globMatches.next());
+      } else {
+        checkState(nonGlobMatches.hasNext(), "Expect nonGlobMatches has next.");
+        matchResults.add(nonGlobMatches.next());
+      }
+    }
+    checkState(!globMatches.hasNext(), "Expect no more elements in globMatches.");
+    checkState(!nonGlobMatches.hasNext(), "Expect no more elements in nonGlobMatches.");
+
+    return matchResults.build();
+  }
+
+  /**
+   * Expands glob expressions to regular expressions.
+   *
+   * @param globExp the glob expression to expand
+   * @return a string with the regular expression this glob expands to
+   */
+  @VisibleForTesting
+  static String wildcardToRegexp(String globExp) {
+    StringBuilder dst = new StringBuilder();
+    char[] src = globExp.replace("**/*", "**").toCharArray();
+    int i = 0;
+    while (i < src.length) {
+      char c = src[i++];
+      switch (c) {
+        case '*':
+          // One char lookahead for **
+          if (i < src.length && src[i] == '*') {
+            dst.append(".*");
+            ++i;
+          } else {
+            dst.append("[^/]*");
+          }
+          break;
+        case '?':
+          dst.append("[^/]");
+          break;
+        case '.':
+        case '+':
+        case '{':
+        case '}':
+        case '(':
+        case ')':
+        case '|':
+        case '^':
+        case '$':
+          // These need to be escaped in regular expressions
+          dst.append('\\').append(c);
+          break;
+        case '\\':
+          i = doubleSlashes(dst, src, i);
+          break;
+        default:
+          dst.append(c);
+          break;
+      }
+    }
+    return dst.toString();
+  }
+
+  private static int doubleSlashes(StringBuilder dst, char[] src, int i) {
+    // Emit the next character without special interpretation
+    dst.append("\\\\");
+    if ((i - 1) != src.length) {
+      dst.append(src[i]);
+      i++;
+    } else {
+      // A backslash at the very end is treated like an escaped backslash
+      dst.append('\\');
+    }
+    return i;
+  }
+
+  private List<MatchResult> matchGlobPaths(List<AzfsResourceId> globs) {
+    return FluentIterable.from(globs).transform(this::expand).toList();
+  }
+
+  /** Expands a pattern into {@link MatchResult}. */
+  @VisibleForTesting
+  MatchResult expand(AzfsResourceId azfsPattern) {
+
+    checkArgument(azfsPattern.isWildcard(), "is Wildcard");
+    String blobPrefix = azfsPattern.getBlobNonWildcardPrefix();
+    Pattern wildcardAsRegexp = Pattern.compile(wildcardToRegexp(azfsPattern.getBlob()));
+
+    LOG.debug(
+        "matching files in container {}, prefix {} against pattern {}",
+        azfsPattern.getContainer(),
+        blobPrefix,
+        wildcardAsRegexp.toString());
+
+    ListBlobsOptions listOptions = new ListBlobsOptions().setPrefix(blobPrefix);
+    Duration timeout = Duration.ZERO.plusMinutes(1);
+
+    String account = azfsPattern.getAccount();
+    String container = azfsPattern.getContainer();
+    BlobContainerClient blobContainerClient = client.get().getBlobContainerClient(container);
+    PagedIterable<BlobItem> blobs = blobContainerClient.listBlobs(listOptions, timeout);
+    List<MatchResult.Metadata> results = new ArrayList<>();
+
+    blobs.forEach(
+        blob -> {
+          String name = blob.getName();
+          if (wildcardAsRegexp.matcher(name).matches() && !name.endsWith("/")) {
+            LOG.debug("Matched object: {}", name);
+
+            BlobProperties properties = blobContainerClient.getBlobClient(name).getProperties();
+            AzfsResourceId rid =
+                AzfsResourceId.fromComponents(account, container, name)
+                    .withSize(properties.getBlobSize())
+                    .withLastModified(Date.from(properties.getLastModified().toInstant()));
+
+            results.add(toMetadata(rid, properties.getContentEncoding()));
+          }
+        });
+
+    return MatchResult.create(MatchResult.Status.OK, results);
+  }
+
+  private MatchResult.Metadata toMetadata(AzfsResourceId path, String contentEncoding) {
+
+    checkArgument(path.getSize().isPresent(), "path has size");
+    boolean isReadSeekEfficient = !NON_READ_SEEK_EFFICIENT_ENCODINGS.contains(contentEncoding);
+
+    return MatchResult.Metadata.builder()
+        .setIsReadSeekEfficient(isReadSeekEfficient)
+        .setResourceId(path)
+        .setSizeBytes(path.getSize().get())
+        .setLastModifiedMillis(path.getLastModified().transform(Date::getTime).or(0L))
+        .build();
+  }
+
+  /**
+   * Returns {@link MatchResult MatchResults} for the given {@link AzfsResourceId paths}.
+   *
+   * <p>The number of returned {@link MatchResult MatchResults} equals to the number of given {@link
+   * AzfsResourceId paths}. Each {@link MatchResult} contains one {@link MatchResult.Metadata}.
+   */
+  @VisibleForTesting
+  private Iterable<MatchResult> matchNonGlobPaths(List<AzfsResourceId> paths) {
+    ImmutableList.Builder<MatchResult> toReturn = ImmutableList.builder();
+    for (AzfsResourceId path : paths) {
+      toReturn.add(toMatchResult(path));
+    }
+    return toReturn.build();
+  }
+
+  private MatchResult toMatchResult(AzfsResourceId path) {
+    BlobClient blobClient =
+        client.get().getBlobContainerClient(path.getContainer()).getBlobClient(path.getBlob());
+    BlobProperties blobProperties;
+
+    try {
+      blobProperties = blobClient.getProperties();
+    } catch (BlobStorageException e) {
+      if (e.getStatusCode() == 404) {
+        return MatchResult.create(MatchResult.Status.NOT_FOUND, new FileNotFoundException());
+      }
+      return MatchResult.create(MatchResult.Status.ERROR, new IOException(e));
+    }
+
+    return MatchResult.create(
+        MatchResult.Status.OK,
+        ImmutableList.of(
+            toMetadata(
+                path.withSize(blobProperties.getBlobSize())
+                    .withLastModified(Date.from(blobProperties.getLastModified().toInstant())),
+                blobProperties.getContentEncoding())));
   }
 
   @Override
   protected WritableByteChannel create(AzfsResourceId resourceId, CreateOptions createOptions)
       throws IOException {
-    // TODO
-    return null;
+    BlobContainerClient blobContainerClient =
+        client.get().getBlobContainerClient(resourceId.getContainer());
+    if (!blobContainerClient.exists()) {
+      throw new UnsupportedOperationException("create does not create containers.");

Review comment:
       Why is it an `UnsupportedOperationException `? Under what kind of condition the `blobContainerClient.exists()` will be `false`?

##########
File path: sdks/java/io/azure/src/test/java/org/apache/beam/sdk/io/azure/blobstore/AzfsTestUtils.java
##########
@@ -0,0 +1,42 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.beam.sdk.io.azure.blobstore;
+
+import com.azure.storage.blob.BlobServiceClient;
+import org.apache.beam.sdk.io.azure.options.BlobstoreOptions;
+import org.apache.beam.sdk.options.PipelineOptionsFactory;
+import org.mockito.Mockito;
+
+class AzfsTestUtils {

Review comment:
       Is it used anywhere?




----------------------------------------------------------------
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

For queries about this service, please contact Infrastructure at:
users@infra.apache.org