Cache last DiskArray APPageIdx when appending to the disk array

kuzudb · Mar 22, 2024 · e16b1e0 · e16b1e0
1 parent 6b4d510
commit e16b1e0
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Showing 2 changed files with 12 additions and 3 deletions.
diff --git a/src/include/storage/storage_structure/disk_array.h b/src/include/storage/storage_structure/disk_array.h
@@ -202,6 +202,7 @@ class BaseDiskArrayInternal {
             auto [apPageIdx, isNewlyAdded] =
                 diskArray.getAPPageIdxAndAddAPToPIPIfNecessaryForWriteTrxNoLock(
                     &header, apCursor.pageIdx);
+            diskArray.lastAPPageIdx = apPageIdx;
             if (isNewlyAdded || walPageIdxAndFrame.originalPageIdx == common::INVALID_PAGE_IDX) {
                 getPage(apPageIdx, isNewlyAdded);
             }
@@ -315,6 +316,8 @@ class BaseDiskArrayInternal {
     std::vector<PIPWrapper> pips;
     PIPUpdates pipUpdates;
     std::shared_mutex diskArraySharedMtx;
+    // For write transactions only
+    common::page_idx_t lastAPPageIdx;
 };
 
 template<typename U>

diff --git a/src/storage/storage_structure/disk_array.cpp b/src/storage/storage_structure/disk_array.cpp
@@ -3,6 +3,7 @@
 #include "common/cast.h"
 #include "common/constants.h"
 #include "common/string_format.h"
+#include "common/types/types.h"
 #include "common/utils.h"
 #include "storage/storage_structure/db_file_utils.h"
 #include "storage/storage_utils.h"
@@ -36,13 +37,15 @@ PIPWrapper::PIPWrapper(FileHandle& fileHandle, page_idx_t pipPageIdx) : pipPageI
 BaseDiskArrayInternal::BaseDiskArrayInternal(
     FileHandle& fileHandle, page_idx_t headerPageIdx, uint64_t elementSize)
     : header{elementSize}, fileHandle{fileHandle}, headerPageIdx{headerPageIdx},
-      hasTransactionalUpdates{false}, bufferManager{nullptr}, wal{nullptr} {}
+      hasTransactionalUpdates{false}, bufferManager{nullptr}, wal{nullptr}, lastAPPageIdx{
+                                                                                INVALID_PAGE_IDX} {}
 
 BaseDiskArrayInternal::BaseDiskArrayInternal(FileHandle& fileHandle, DBFileID dbFileID,
     page_idx_t headerPageIdx, BufferManager* bufferManager, WAL* wal,
     transaction::Transaction* transaction)
     : fileHandle{fileHandle}, dbFileID{dbFileID}, headerPageIdx{headerPageIdx},
-      hasTransactionalUpdates{false}, bufferManager{bufferManager}, wal{wal} {
+      hasTransactionalUpdates{false}, bufferManager{bufferManager}, wal{wal},
+      lastAPPageIdx{INVALID_PAGE_IDX} {
     auto [fileHandleToPin, pageIdxToPin] = DBFileUtils::getFileHandleAndPhysicalPageIdxToPin(
         ku_dynamic_cast<FileHandle&, BMFileHandle&>(fileHandle), headerPageIdx, *wal,
         transaction->getType());
@@ -146,6 +149,7 @@ uint64_t BaseDiskArrayInternal::pushBackNoLock(std::span<uint8_t> val) {
             auto apCursor = getAPIdxAndOffsetInAP(elementIdx);
             auto [apPageIdx, isNewlyAdded] = getAPPageIdxAndAddAPToPIPIfNecessaryForWriteTrxNoLock(
                 (DiskArrayHeader*)frame, apCursor.pageIdx);
+            lastAPPageIdx = apPageIdx;
             // Now do the push back.
             DBFileUtils::updatePage((BMFileHandle&)(fileHandle), dbFileID, apPageIdx, isNewlyAdded,
                 *bufferManager, *wal, [&apCursor, &val](uint8_t* frame) -> void {
@@ -287,7 +291,9 @@ uint64_t BaseDiskArrayInternal::readUInt64HeaderFieldNoLock(
 std::pair<page_idx_t, bool>
 BaseDiskArrayInternal::getAPPageIdxAndAddAPToPIPIfNecessaryForWriteTrxNoLock(
     DiskArrayHeader* updatedDiskArrayHeader, page_idx_t apIdx) {
-    if (apIdx < updatedDiskArrayHeader->numAPs) {
+    if (apIdx == updatedDiskArrayHeader->numAPs - 1 && lastAPPageIdx != INVALID_PAGE_IDX) {
+        return std::make_pair(lastAPPageIdx, false /*not a new page*/);
+    } else if (apIdx < updatedDiskArrayHeader->numAPs) {
         // If the apIdx of the array page is < updatedDiskArrayHeader->numAPs, we do not have to
         // add a new array page, so directly return the pageIdx of the apIdx.
         return std::make_pair(getAPPageIdxNoLock(apIdx, TransactionType::WRITE),