[GitHub] [trafficserver] randall commented on a change in pull request #6455: regex_revalidate c++ and lifecycle message reload

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

randall commented on a change in pull request #6455:
URL: https://github.com/apache/trafficserver/pull/6455#discussion_r603689715



##########
File path: plugins/regex_revalidate/regex_revalidate.cc
##########
@@ -0,0 +1,729 @@
+/** @file
+
+  @section license License
+
+  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.
+ */
+
+#include "ts/ts.h"
+#include "ts/remap.h"
+#include "ts/experimental.h"
+#include "regex.h"
+
+#include <cinttypes>
+#include <cstring>
+#include <ctime>
+#include <getopt.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include <algorithm>
+#include <iostream>
+#include <map>
+#include <memory>
+#include <set>
+#include <string>
+#include <string_view>
+#include <vector>
+
+#ifdef HAVE_PCRE_PCRE_H
+#include <pcre/pcre.h>
+#else
+#include <pcre.h>
+#endif
+
+namespace
+{
+constexpr char const *const PLUGIN_NAME = "regex_revalidate";
+constexpr char const *const RELOAD_TAG  = "config_reload";
+constexpr char const *const PRINT_TAG   = "config_print";
+
+#define DEBUG_LOG(fmt, ...) TSDebug(PLUGIN_NAME, "%s:%d " fmt, __func__, __LINE__, ##__VA_ARGS__)
+
+#define ERROR_LOG(fmt, ...)                         \
+  TSError("(%s) " fmt, PLUGIN_NAME, ##__VA_ARGS__); \
+  DEBUG_LOG(fmt, ##__VA_ARGS__)
+
+constexpr TSHRTime const CONFIG_TMOUT = 60000; // ms, 60s
+// constexpr TSHRTime const CONFIG_TMOUT = 5000; // ms, 5
+constexpr int const OVECTOR_SIZE      = 30;
+constexpr int const LOG_ROLL_INTERVAL = 86400;
+constexpr int const LOG_ROLL_OFFSET   = 0;
+
+TSCont config_cont{nullptr};
+Regex config_re;
+
+void *
+ts_malloc(size_t s)
+{
+  return TSmalloc(s);
+}
+
+void
+ts_free(void *s)
+{
+  return TSfree(s);
+}
+
+struct Invalidate {
+  std::string regex_text{};
+  Regex regex{};
+  time_t epoch{0};
+  time_t expiry{0};
+
+  Invalidate() = default;
+
+  Invalidate(Invalidate const &orig)
+  {
+    regex_text = orig.regex_text;
+    epoch      = orig.epoch;
+    expiry     = orig.expiry;
+    regex.compile(regex_text.c_str());
+  }
+
+  Invalidate(Invalidate &&orig) = default;
+  Invalidate &operator=(Invalidate &&rhs) = default;
+
+  Invalidate &
+  operator=(Invalidate const &rhs)
+  {
+    if (&rhs != this) {
+      regex_text = rhs.regex_text;
+      epoch      = rhs.epoch;
+      expiry     = rhs.expiry;
+      regex.compile(regex_text.c_str());
+    }
+    return *this;
+  }
+
+  ~Invalidate() = default;
+
+  inline bool
+  is_valid() const
+  {
+    return regex.is_valid();
+  }
+
+  inline bool
+  matches(char const *const url, int const url_len) const
+  {
+    return regex.matches(std::string_view{url, (unsigned)url_len});
+  }
+
+  static Invalidate fromLine(time_t const epoch, Regex const &config_re, char *const line);
+};
+
+struct PluginState {
+  std::string config_file{};
+  std::shared_ptr<std::vector<Invalidate>> invalidate_vec;
+  bool timed_reload{true};
+  time_t config_file_mtime{0};
+  time_t min_expiry{0};
+  TSTextLogObject log{nullptr};
+
+  ~PluginState()
+  {
+    if (nullptr != log) {
+      TSTextLogObjectDestroy(log);
+    }
+  }
+
+  bool fromArgs(int argc, char const **argv);
+  bool loadConfig(time_t const timenow, std::vector<Invalidate> *const newrules) const;
+
+  void printConfig() const;
+  void logConfig() const;
+};
+
+Invalidate
+Invalidate::fromLine(time_t const epoch, Regex const &config_re, char *const line)
+{
+  Invalidate rule;
+
+  int ovector[OVECTOR_SIZE];
+  DEBUG_LOG("'%s'", line);
+  int const rc = config_re.exec(line, ovector, OVECTOR_SIZE);
+
+  if (3 == rc) {
+    int const regbeg = ovector[2];
+    int const regend = ovector[3];
+
+    char const *const regstr = line + regbeg;
+    char const oldch         = line[regend];
+    line[regend]             = '\0'; // temporarily inject null termination
+
+    if (rule.regex.compile(regstr)) {
+      rule.regex_text = regstr;
+      rule.expiry     = (time_t)atoll(line + ovector[4]);
+      rule.epoch      = epoch;
+    } else {
+      DEBUG_LOG("Invalid regex in line: '%s'", regstr);
+    }
+
+    // restore the line char*
+    line[regend] = oldch;
+  }
+
+  return rule;
+}
+
+void
+get_time_now_str(char *const buf, size_t const buflen)
+{
+  TSHRTime const timenowusec = TShrtime();
+  int64_t const timemsec     = (int64_t)(timenowusec / 1000000);
+  time_t const timesec       = (time_t)(timemsec / 1000);
+  int const ms               = (int)(timemsec % 1000);
+
+  struct tm tm;
+  gmtime_r(&timesec, &tm);
+  size_t const dtlen = strftime(buf, buflen, "%b %e %H:%M:%S", &tm);
+
+  // tack on the ms
+  snprintf(buf + dtlen, buflen - dtlen, ".%03d", ms);
+}
+
+void
+PluginState::printConfig() const
+{
+  char timebuf[64] = {'\0'};
+  get_time_now_str(timebuf, sizeof(timebuf));
+
+  fprintf(stderr, "[%s] %s config file: %s\n", timebuf, PLUGIN_NAME, config_file.c_str());
+
+  if (invalidate_vec) {
+    for (Invalidate const &iv : *invalidate_vec) {
+      fprintf(stderr, "[%s] %s line: '%s' epoch: %ju expiry: %ju\n", timebuf, PLUGIN_NAME, iv.regex_text.c_str(),
+              (uintmax_t)iv.epoch, (uintmax_t)iv.expiry);
+    }
+  } else {
+    fprintf(stderr, "[%s] %s config: EMPTY\n", timebuf, PLUGIN_NAME);
+  }
+
+  fflush(stderr);
+}
+
+void
+PluginState::logConfig() const
+{
+  TSDebug(PLUGIN_NAME, "Current config: %s", config_file.c_str());
+  if (nullptr != log) {
+    TSTextLogObjectWrite(log, "Current config: %s", config_file.c_str());
+  }
+
+  if (invalidate_vec) {
+    for (Invalidate const &iv : *invalidate_vec) {
+      TSDebug(PLUGIN_NAME, "line: '%s' epoch: %ju expiry: %ju", iv.regex_text.c_str(), (uintmax_t)iv.epoch, (uintmax_t)iv.expiry);
+      if (nullptr != log) {
+        TSTextLogObjectWrite(log, "line: '%s' epoch: %ju expiry: %ju", iv.regex_text.c_str(), (uintmax_t)iv.epoch,
+                             (uintmax_t)iv.expiry);
+      }
+    }
+  } else {
+    TSDebug(PLUGIN_NAME, "Configuration EMPTY");
+    if (nullptr != log) {
+      TSTextLogObjectWrite(log, "EMPTY");
+    }
+  }
+}
+
+bool
+PluginState::fromArgs(int argc, char const **argv)
+{
+  int c;
+  constexpr option const longopts[] = {
+    {"config", required_argument, nullptr, 'c'},
+    {"disable-timed-reload", no_argument, nullptr, 'd'},
+    {"log", required_argument, nullptr, 'l'},
+    {nullptr, 0, nullptr, 0},
+  };
+
+  while ((c = getopt_long(argc, (char *const *)argv, "c:l:d", longopts, nullptr)) != -1) {
+    switch (c) {
+    case 'c':
+      config_file = optarg;
+
+      // path is relative to config dir
+      if ('/' != config_file[0]) {
+        config_file = std::string(TSConfigDirGet()) + "/" + config_file;
+      }
+
+      DEBUG_LOG("Config File: %s", config_file.c_str());
+      break;
+    case 'l':
+      if (TS_SUCCESS == TSTextLogObjectCreate(optarg, TS_LOG_MODE_ADD_TIMESTAMP, &log)) {
+        TSTextLogObjectRollingEnabledSet(log, 1);
+        TSTextLogObjectRollingIntervalSecSet(log, LOG_ROLL_INTERVAL);
+        TSTextLogObjectRollingOffsetHrSet(log, LOG_ROLL_OFFSET);
+        DEBUG_LOG("Logging Mode enabled");
+      }
+      break;
+    case 'd':
+      timed_reload = false;
+      DEBUG_LOG("Timed reload disabled (disable-timed-reload)");
+      break;
+    default:
+      break;
+    }
+  }
+
+  if (config_file.empty()) {
+    ERROR_LOG("Plugin requires a --config option along with a config file name");
+    return false;
+  }
+
+  return true;
+}
+
+time_t
+timeForFile(std::string const &filepath)
+{
+  time_t mtime{0};
+  struct stat fstat;
+  if (0 == stat(filepath.c_str(), &fstat)) {
+    mtime = fstat.st_mtime;
+  } else {
+    DEBUG_LOG("Could not stat %s", filepath.c_str());
+  }
+  return mtime;
+}
+
+// load config, true if rules changed
+bool
+PluginState::loadConfig(time_t const timenow, std::vector<Invalidate> *const rules) const
+{
+  TSAssert(nullptr != rules);
+
+  FILE *const fs = fopen(config_file.c_str(), "r");
+  if (nullptr == fs) {
+    DEBUG_LOG("Could not open %s for reading", config_file.c_str());
+    return false;
+  }
+
+  // load from file
+  std::vector<Invalidate> loaded;
+  int lineno = 0;
+  char line[LINE_MAX];
+  while (nullptr != fgets(line, LINE_MAX, fs)) {
+    ++lineno;
+    line[strcspn(line, "\r\n")] = '\0';
+    if (0 < strlen(line) && '#' != line[0]) {
+      Invalidate rnew = Invalidate::fromLine(timenow, config_re, line);
+      if (rnew.is_valid()) {
+        loaded.push_back(std::move(rnew));
+      } else {
+        DEBUG_LOG("Invalid rule '%s' from line: '%d'", line, lineno);
+      }
+    }
+  }
+
+  fclose(fs);
+
+  if (loaded.empty()) {
+    DEBUG_LOG("No rules loaded from file '%s'", config_file.c_str());
+    return false;
+  }
+
+  // stable sort to make clearing duplicates easy
+  std::stable_sort(loaded.begin(), loaded.end(),
+                   [](Invalidate const &lhs, Invalidate const &rhs) { return lhs.regex_text < rhs.regex_text; });
+
+  // sweep to clear duplicates, last one wins
+  for (size_t index = 0; index < (loaded.size() - 1); ++index) {
+    if (loaded[index].regex_text == loaded[index + 1].regex_text) {
+      loaded[index] = Invalidate{};
+    }
+  }
+
+  if (!this->invalidate_vec || this->invalidate_vec->empty()) {
+    DEBUG_LOG("Installing fresh rules");
+    *rules = std::move(loaded);
+    return true;
+  }
+
+  DEBUG_LOG("Merging new config");
+
+  // merge loaded and current rule set
+  auto const &cur = *(this->invalidate_vec);
+  auto itload     = loaded.begin();
+  auto itcur      = cur.cbegin();
+
+  bool changed = false;
+
+  // reimplementation of std::set_union
+  while (cur.cend() != itcur) {
+    if (loaded.cend() == itload) {
+      std::copy(itcur, cur.cend(), rules->end());
+      break;
+    }
+
+    // fast forward over cleared items
+    while (!itload->is_valid()) {
+      DEBUG_LOG("Skipping cleared duplicate rule");
+      ++itload;
+      TSAssert(loaded.end() != itload); // last item will always be valid.
+    }
+
+    int const cmp = itload->regex_text.compare(itcur->regex_text);
+    if (cmp < 0) {
+      if (timenow < itload->expiry) {
+        DEBUG_LOG("Adding new rule: '%s'", itload->regex_text.c_str());
+        rules->push_back(std::move(*itload));
+        changed = true;
+      } else {
+        DEBUG_LOG("Not adding new expired rule: '%s'", itload->regex_text.c_str());
+      }
+      ++itload;
+    } else if (0 < cmp) {
+      DEBUG_LOG("Retaining old rule: '%s'", itcur->regex_text.c_str());
+      rules->push_back(*itcur);
+      ++itcur;
+    } else {
+      if (itload->expiry != itcur->expiry) {
+        DEBUG_LOG("Updating rule: '%s'", itload->regex_text.c_str());
+        rules->push_back(std::move(*itload));
+        changed = true;
+      } else {
+        DEBUG_LOG("Using old rule: '%s'", itcur->regex_text.c_str());
+        rules->push_back(*itcur);
+      }
+      ++itcur;
+      ++itload;
+    }
+  }
+
+  // any leftover loaded rules get tacked on
+  while (loaded.end() != itload) {
+    DEBUG_LOG("Adding new rule: '%s'", itload->regex_text.c_str());
+    rules->push_back(std::move(*itload));
+    ++itload;
+    changed = true;
+  }
+
+  DEBUG_LOG("Rules have been changed: '%s'", changed ? "true" : "false");
+
+  return changed;
+}
+
+// remove expired rules
+bool
+pruneConfig(time_t const timenow, std::vector<Invalidate> *const rules, time_t *const min_expiry)
+{
+  TSAssert(nullptr != rules);
+  TSAssert(nullptr != min_expiry);
+
+  bool pruned = false;
+  if (timenow < *min_expiry || nullptr == rules) {
+    return pruned;
+  }
+
+  // recalculate min_expiry
+  *min_expiry = std::numeric_limits<time_t>::max();
+
+  std::vector<Invalidate>::iterator itvec(rules->begin());
+
+  while (rules->end() != itvec) {
+    Invalidate const &inv = *itvec;
+
+    if (inv.expiry < timenow) {
+      DEBUG_LOG("Removing rule: %s", inv.regex_text.c_str());
+      std::swap(*itvec, rules->back());
+      rules->pop_back();
+      pruned = true;
+    } else {
+      *min_expiry = std::min(*min_expiry, inv.expiry);
+      ++itvec;
+    }
+  }
+
+  if (pruned && rules->empty()) {
+    DEBUG_LOG("All rules pruned");
+  }
+
+  return pruned;
+}
+
+int
+config_handler(TSCont config_cont, TSEvent event, void *edata)
+{
+  DEBUG_LOG("config_handler, event: %d", event);
+
+  // config_cont's mutex is already locked
+  PluginState *const pstate = static_cast<PluginState *>(TSContDataGet(config_cont));
+
+  bool should_reload = false;
+
+  switch (event) {
+  case TS_EVENT_TIMEOUT: {
+    should_reload = pstate->timed_reload;
+  } break;
+  case TS_EVENT_MGMT_UPDATE: {
+    should_reload = true;
+  } break;
+  case TS_EVENT_LIFECYCLE_MSG: {
+    // ensure the message is for regex_revalidate
+    TSPluginMsg *const msgp = (TSPluginMsg *)edata;
+    if (0 == strncasecmp(msgp->tag, PLUGIN_NAME, strlen(msgp->tag))) {
+      char const *const msgstr = static_cast<char const *>(msgp->data);
+      int const msglen         = static_cast<int>(msgp->data_size);
+      DEBUG_LOG("Lifecycle plugin message received: %.*s", msglen, msgstr);
+      if (0 == strncasecmp(msgstr, RELOAD_TAG, msglen)) {
+        should_reload = true;
+      } else if (0 == strncasecmp(msgstr, PRINT_TAG, msglen)) {
+        pstate->printConfig();
+      } else {
+        ERROR_LOG("Unrecognized lifecycle message %.*s", msglen, msgstr);
+      }
+    }
+  } break;
+  default: // unknown message
+    return 0;
+    break;
+  }
+
+  time_t const timenow = time(nullptr);
+
+  bool rules_changed = false;
+  std::vector<Invalidate> newrules;
+
+  if (should_reload) {
+    time_t const mtime = timeForFile(pstate->config_file);
+    if (mtime != pstate->config_file_mtime) {
+      rules_changed             = pstate->loadConfig(timenow, &newrules);
+      pstate->config_file_mtime = mtime;
+
+      // this sets off a new min expiry scan
+      if (rules_changed) {
+        pstate->min_expiry = 0;
+      }
+    }
+  }
+
+  // prune
+  if (pstate->min_expiry < timenow) {
+    if (newrules.empty()) {
+      newrules = *(pstate->invalidate_vec);
+    }
+
+    time_t new_expiry  = 0;
+    bool const pruned  = pruneConfig(timenow, &newrules, &new_expiry);
+    pstate->min_expiry = new_expiry;
+
+    if (pruned) {
+      rules_changed = true;
+    }
+  }
+
+  if (rules_changed) {
+    auto vecnew = std::make_shared<std::vector<Invalidate>>(std::move(newrules));
+
+    std::atomic_store(&(pstate->invalidate_vec), vecnew);
+    DEBUG_LOG("New configuation installed");
+    pstate->logConfig();
+  }
+
+  // Reschedule the continuous pruning/reload job
+  if (TS_EVENT_TIMEOUT == event) {
+    TSContScheduleOnPool(config_cont, CONFIG_TMOUT, TS_THREAD_POOL_TASK);
+  }
+
+  return 0;
+}
+
+time_t
+get_date_from_cached_hdr(TSHttpTxn txn)
+{
+  TSMBuffer buf;
+  TSMLoc hdr_loc, date_loc;
+  time_t date = 0;
+
+  if (TSHttpTxnCachedRespGet(txn, &buf, &hdr_loc) == TS_SUCCESS) {
+    date_loc = TSMimeHdrFieldFind(buf, hdr_loc, TS_MIME_FIELD_DATE, TS_MIME_LEN_DATE);
+    if (nullptr != date_loc) {
+      date = TSMimeHdrFieldValueDateGet(buf, hdr_loc, date_loc);
+      TSHandleMLocRelease(buf, hdr_loc, date_loc);
+    }
+    TSHandleMLocRelease(buf, nullptr, hdr_loc);
+  }
+
+  return date;
+}
+
+int
+main_handler(TSCont cont, TSEvent event, void *edata)
+{
+  TSHttpTxn txn = (TSHttpTxn)edata;
+  int status    = TS_ERROR;
+
+  switch (event) {
+  case TS_EVENT_HTTP_CACHE_LOOKUP_COMPLETE:
+    if (TSHttpTxnCacheLookupStatusGet(txn, &status) == TS_SUCCESS) {
+      if (status == TS_CACHE_LOOKUP_HIT_FRESH) {
+        PluginState *const pstate = static_cast<PluginState *>(TSContDataGet(cont));
+        // atomcally grab a handle
+        using InvHandle        = std::shared_ptr<std::vector<Invalidate>>;
+        InvHandle const vecinv = std::atomic_load(&(pstate->invalidate_vec));
+
+        if (vecinv) {
+          time_t const date    = get_date_from_cached_hdr(txn);
+          time_t const timenow = time(nullptr);
+          char *url            = nullptr;
+          int url_len          = 0;
+
+          for (Invalidate const &inv : *vecinv) {
+            if (date <= inv.epoch && timenow <= inv.expiry) {
+              if (nullptr == url) {
+                url = TSHttpTxnEffectiveUrlStringGet(txn, &url_len);
+              }
+
+              if (nullptr == url || 0 == url_len) {
+                break;
+              } else if (inv.matches(url, url_len)) {
+                TSHttpTxnCacheLookupStatusSet(txn, TS_CACHE_LOOKUP_HIT_STALE);
+                DEBUG_LOG("Forced revalidate - %.*s", url_len, url);
+                break;
+              }
+            }
+          }
+
+          if (nullptr != url) {
+            TSfree(url);
+          }
+        }
+      }
+    }
+    break;
+  case TS_EVENT_HTTP_TXN_CLOSE: // never called by global
+    TSContDestroy(cont);
+    break;
+  default:
+    break;
+  }
+
+  TSHttpTxnReenable(txn, TS_EVENT_HTTP_CONTINUE);
+  return 0;
+}
+
+} // namespace
+
+namespace
+{
+void
+setup_memory_allocation()
+{
+  if (&ts_malloc != pcre_malloc) {

Review comment:
       This should be removed (like what was done in #7608)




-- 
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