Allow returning result for write queries

sqlitecluster/SQLite.cpp

@@ -566,18 +566,25 @@ bool SQLite::write(const string& query) {
     }
 
     // This is literally identical to the idempotent version except for the check for _noopUpdateMode.
-    return _writeIdempotent(query);
+    SQResult ignore;
+    return _writeIdempotent(query, ignore);
 }
 
 bool SQLite::writeIdempotent(const string& query) {
-    return _writeIdempotent(query);
+    SQResult ignore;
+    return _writeIdempotent(query, ignore);
+}
+
+bool SQLite::writeIdempotent(const string& query, SQResult& result) {
+    return _writeIdempotent(query, result);
 }
 
 bool SQLite::writeUnmodified(const string& query) {
-    return _writeIdempotent(query, true);
+    SQResult ignore;
+    return _writeIdempotent(query, ignore, true);
 }
 
-bool SQLite::_writeIdempotent(const string& query, bool alwaysKeepQueries) {
+bool SQLite::_writeIdempotent(const string& query, SQResult& result, bool alwaysKeepQueries) {
     SASSERT(_insideTransaction);
     _queryCache.clear();
     _queryCount++;
@@ -600,7 +607,7 @@ bool SQLite::_writeIdempotent(const string& query, bool alwaysKeepQueries) {
     {
         shared_lock<shared_mutex> lock(_sharedData.writeLock);
         if (_enableRewrite) {
-            resultCode = SQuery(_db, "read/write transaction", query, 2'000'000, true);
+            resultCode = SQuery(_db, "read/write transaction", query, result, 2'000'000, true);
             if (resultCode == SQLITE_AUTH) {
                 // Run re-written query.
                 _currentlyRunningRewritten = true;
@@ -610,7 +617,7 @@ bool SQLite::_writeIdempotent(const string& query, bool alwaysKeepQueries) {
                 _currentlyRunningRewritten = false;
             }
         } else {
-            resultCode = SQuery(_db, "read/write transaction", query);
+            resultCode = SQuery(_db, "read/write transaction", query, result);
         }
     }
 

sqlitecluster/SQLite.h

@@ -1,5 +1,6 @@
 #pragma once
 #include <libstuff/sqlite3.h>
+#include <libstuff/SQResult.h>
 #include <libstuff/SPerformanceTimer.h>
 
 class SQLite {
@@ -109,6 +110,10 @@ class SQLite {
     // known to be repeatable. What counts as repeatable is up to the individual command.
     bool writeIdempotent(const string& query);
 
+    // Executes a write query and retrieves the result.
+    // Designed for use with queries that include a RETURNING clause
+    bool writeIdempotent(const string& query, SQResult& result);
+
     // This runs a query completely unchanged, always adding it to the uncommitted query, such that it will be recorded
     // in the journal even if it had no effect on the database. This lets replicated or synchronized queries be added
     // to the journal *even if they have no effect* on the rest of the database.
@@ -400,7 +405,7 @@ class SQLite {
     static thread_local int64_t _conflictPage;
     static thread_local string _conflictTable;
 
-    bool _writeIdempotent(const string& query, bool alwaysKeepQueries = false);
+    bool _writeIdempotent(const string& query, SQResult& result, bool alwaysKeepQueries = false);
 
     // Constructs a UNION query from a list of 'query parts' over each of our journal tables.
     // Fore each table, queryParts will be joined with that table's name as a separator. I.e., if you have a tables