From cf17515e409440eecfb04bf7186790d8baa8ab12 Mon Sep 17 00:00:00 2001
From: David Steele <david@pgmasters.net>
Date: Fri, 8 Mar 2024 12:34:11 +1300
Subject: [PATCH] Improve archive-push WAL segment queue handling.

Infer the size of all WAL segments from the size of the first segment rather than getting info for all segments (up to queue size). If the segments are not the same size then there are larger issues than the WAL queue.
---
 doc/xml/release/2024/2.51.xml             | 11 ++++++++++
 src/command/archive/push/push.c           | 25 ++++++++---------------
 test/src/module/command/archivePushTest.c |  3 +++
 3 files changed, 23 insertions(+), 16 deletions(-)

diff --git a/doc/xml/release/2024/2.51.xml b/doc/xml/release/2024/2.51.xml
index ced19c88e..17c9d220e 100644
--- a/doc/xml/release/2024/2.51.xml
+++ b/doc/xml/release/2024/2.51.xml
@@ -30,6 +30,17 @@
         </release-bug-list>
 
         <release-improvement-list>
+            <release-item>
+                <github-pull-request id="2277"/>
+
+                <release-item-contributor-list>
+                    <release-item-contributor id="david.steele"/>
+                    <release-item-reviewer id="stephen.frost"/>
+                </release-item-contributor-list>
+
+                <p>Improve <cmd>archive-push</cmd> WAL segment queue handling.</p>
+            </release-item>
+
             <release-item>
                 <github-pull-request id="2263"/>
 
diff --git a/src/command/archive/push/push.c b/src/command/archive/push/push.c
index 4e29c5610..6f19d2541 100644
--- a/src/command/archive/push/push.c
+++ b/src/command/archive/push/push.c
@@ -60,37 +60,30 @@ archivePushDropWarning(const String *const walFile, const uint64_t queueMax)
 Determine if the WAL process list has become large enough to drop
 ***********************************************************************************************************************************/
 static bool
-archivePushDrop(const String *walPath, const StringList *const processList)
+archivePushDrop(const String *const walPath, const StringList *const processList)
 {
     FUNCTION_LOG_BEGIN(logLevelDebug);
         FUNCTION_LOG_PARAM(STRING, walPath);
         FUNCTION_LOG_PARAM(STRING_LIST, processList);
     FUNCTION_LOG_END();
 
+    ASSERT(walPath != NULL);
+    ASSERT(processList != NULL);
+
     const uint64_t queueMax = cfgOptionUInt64(cfgOptArchivePushQueueMax);
     uint64_t queueSize = 0;
-    bool result = false;
 
-    MEM_CONTEXT_TEMP_RESET_BEGIN()
+    MEM_CONTEXT_TEMP_BEGIN()
     {
-        for (unsigned int processIdx = 0; processIdx < strLstSize(processList); processIdx++)
+        if (!strLstEmpty(processList))
         {
-            queueSize += storageInfoP(
-                storagePg(), strNewFmt("%s/%s", strZ(walPath), strZ(strLstGet(processList, processIdx)))).size;
-
-            if (queueSize > queueMax)
-            {
-                result = true;
-                break;
-            }
-
-            // Reset the memory context occasionally so we don't use too much memory or slow down processing
-            MEM_CONTEXT_TEMP_RESET(1000);
+            queueSize = storageInfoP(
+                storagePg(), strNewFmt("%s/%s", strZ(walPath), strZ(strLstGet(processList, 0)))).size * strLstSize(processList);
         }
     }
     MEM_CONTEXT_TEMP_END();
 
-    FUNCTION_LOG_RETURN(BOOL, result);
+    FUNCTION_LOG_RETURN(BOOL, queueSize > queueMax);
 }
 
 /***********************************************************************************************************************************
diff --git a/test/src/module/command/archivePushTest.c b/test/src/module/command/archivePushTest.c
index 320f795fe..8eae4fc3b 100644
--- a/test/src/module/command/archivePushTest.c
+++ b/test/src/module/command/archivePushTest.c
@@ -90,6 +90,9 @@ testRun(void)
 
         TEST_RESULT_BOOL(
             archivePushDrop(STRDEF("pg_wal"), archivePushProcessList(STRDEF(TEST_PATH "/db/pg_wal"))), true, "wal is dropped");
+
+        // No WAL to be processed
+        TEST_RESULT_BOOL(archivePushDrop(STRDEF("pg_wal"), strLstNew()), false, "no WAL to be processed");
     }
 
     // *****************************************************************************************************************************