[couchdb-erlfdb] 01/01: Add support for reporting conflicting keys

[da...@apache.org]

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davisp pushed a commit to branch report-conflicting-keys
in repository https://gitbox.apache.org/repos/asf/couchdb-erlfdb.git

commit 5c81514a6465f6a5809ac2255e3b37677be46f93
Author: Paul J. Davis <pa...@gmail.com>
AuthorDate: Wed Sep 2 13:55:27 2020 -0500

    Add support for reporting conflicting keys
    
    Transactions that fail due to a conflict can be hard to debug. This
    exposes a recent feature that reports keys that were in conflict if a
    transaction has to be retried due to a conflict.
---
 c_src/atom_names.h | 1 +
 c_src/main.c       | 2 ++
 src/erlfdb.erl     | 9 +++++++++
 3 files changed, 12 insertions(+)

diff --git a/c_src/atom_names.h b/c_src/atom_names.h
index 0a6b1ad..98b5c4f 100644
--- a/c_src/atom_names.h
+++ b/c_src/atom_names.h
@@ -107,6 +107,7 @@ ATOM_MAP(allow_writes);
 ATOM_MAP(disallow_writes);
 ATOM_MAP(include_port_in_address);
 ATOM_MAP(use_provisional_proxies);
+ATOM_MAP(report_conflicting_keys);
 
 
 // Streaming mode
diff --git a/c_src/main.c b/c_src/main.c
index b693f06..0893e9f 100644
--- a/c_src/main.c
+++ b/c_src/main.c
@@ -946,6 +946,8 @@ erlfdb_transaction_set_option(
         option = FDB_TR_OPTION_SIZE_LIMIT;
     } else if(IS_ATOM(argv[1], use_provisional_proxies)) {
         option = FDB_TR_OPTION_USE_PROVISIONAL_PROXIES;
+    } else if(IS_ATOM(argv[1], report_conflicting_keys)) {
+        option = FDB_TR_OPTION_REPORT_CONFLICTING_KEYS;
     } else {
         return enif_make_badarg(env);
     }
diff --git a/src/erlfdb.erl b/src/erlfdb.erl
index 240925f..56ea4f7 100644
--- a/src/erlfdb.erl
+++ b/src/erlfdb.erl
@@ -115,6 +115,9 @@
     % Locality
     get_addresses_for_key/2,
 
+    % Get conflict information
+    get_conflicting_keys/1,
+
     % Misc
     on_error/2,
     error_predicate/2,
@@ -629,6 +632,12 @@ get_addresses_for_key(?IS_SS = SS, Key) ->
     get_addresses_for_key(?GET_TX(SS), Key).
 
 
+get_conflicting_keys(?IS_TX = Tx) ->
+    StartKey = <<16#FF, 16#FF, "/transaction/conflicting_keys/">>,
+    EndKey = <<16#FF, 16#FF, "/transaction/conflicting_keys/", 16#FF>>,
+    get_range(Tx, StartKey, EndKey).
+
+
 on_error(?IS_TX = Tx, {erlfdb_error, ErrorCode}) ->
     on_error(Tx, ErrorCode);