From 2d3e7ce4cc17ccd383bc1781a129e779ce5e8056 Mon Sep 17 00:00:00 2001
From: Tyler Karaszewski <tyler@expensify.com>
Date: Thu, 31 Aug 2023 16:04:01 -0700
Subject: [PATCH] Add flag to allow running 'prepare' with no writes

---
 BedrockCommand.cpp | 5 +++++
 BedrockCommand.h   | 7 +++++++
 BedrockCore.cpp    | 2 +-
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/BedrockCommand.cpp b/BedrockCommand.cpp
index 6bcde4a69..931874684 100644
--- a/BedrockCommand.cpp
+++ b/BedrockCommand.cpp
@@ -20,6 +20,7 @@ BedrockCommand::BedrockCommand(SQLiteCommand&& baseCommand, BedrockPlugin* plugi
     socket(nullptr),
     scheduledTime(request.isSet("commandExecuteTime") ? request.calc64("commandExecuteTime") : STimeNow()),
     _plugin(plugin),
+    _commitEmptyTransactions(false),
     _inProgressTiming(INVALID, 0, 0),
     _timeout(_getTimeout(request, scheduledTime))
 {
@@ -298,3 +299,7 @@ void BedrockCommand::setTimeout(uint64_t timeoutDurationMS) {
     timeoutDurationMS += STimeNow();
     _timeout = timeoutDurationMS;
 }
+
+bool BedrockCommand::shouldCommitEmptyTransactions() const {
+    return _commitEmptyTransactions;
+}
diff --git a/BedrockCommand.h b/BedrockCommand.h
index 602191d4d..d385de33d 100644
--- a/BedrockCommand.h
+++ b/BedrockCommand.h
@@ -207,10 +207,17 @@ class BedrockCommand : public SQLiteCommand {
     // Time at which this command was initially scheduled (typically the time of creation).
     const uint64_t scheduledTime;
 
+    // Returns _commitEmptyTransactions.
+    bool shouldCommitEmptyTransactions() const;
+
   protected:
     // The plugin that owns this command.
     BedrockPlugin* _plugin;
 
+    // Commands can set this flag to indicate they want the commit process to be run even though it doesn't appear that any writes have occurred.
+    // The main use of this is to cause commands that use SQLite::onPrepareHandler to do additional writing to run these final writes.
+    bool _commitEmptyTransactions;
+
   private:
     // Set certain initial state on construction. Common functionality to several constructors.
     void _init();
diff --git a/BedrockCore.cpp b/BedrockCore.cpp
index 9cfec2805..c7c1015f6 100644
--- a/BedrockCore.cpp
+++ b/BedrockCore.cpp
@@ -278,7 +278,7 @@ BedrockCore::RESULT BedrockCore::processCommand(unique_ptr<BedrockCommand>& comm
         }
 
         // If we have no uncommitted query, just rollback the empty transaction. Otherwise, we need to commit.
-        if (_db.getUncommittedQuery().empty()) {
+        if (_db.getUncommittedQuery().empty() && !command->shouldCommitEmptyTransactions()) {
             _db.rollback();
         } else {
             needsCommit = true;