Ensure that empty space on pages is zeroed before they are written to disk.

This helps with compressed databases, and stops valgrind complaining about
uninitialized bytes and write().

FossilOrigin-Name: 5ffec5db33137251090d45e2ca7e3e7823e3215ae89822d905923424ceba2ac2

diff --git a/ext/lsm1/lsm_sorted.c b/ext/lsm1/lsm_sorted.c
index f479f4ce8cfffca012640465cc3db58197303e2c..9eff2d08cc3d7e423a42719853aa3dd4056d8937 100644 (file)
--- a/ext/lsm1/lsm_sorted.c
+++ b/ext/lsm1/lsm_sorted.c
@@ -92,7 +92,7 @@
 #define SEGMENT_POINTER_OFFSET(pgsz)        ((pgsz) - 2 - 2 - 8)
 #define SEGMENT_CELLPTR_OFFSET(pgsz, iCell) ((pgsz) - 2 - 2 - 8 - 2 - (iCell)*2)
 
-#define SEGMENT_EOF(pgsz, nEntry) SEGMENT_CELLPTR_OFFSET(pgsz, nEntry)
+#define SEGMENT_EOF(pgsz, nEntry) SEGMENT_CELLPTR_OFFSET(pgsz, nEntry-1)
 
 #define SEGMENT_BTREE_FLAG     0x0001
 #define PGFTR_SKIP_NEXT_FLAG   0x0002
@@ -3999,6 +3999,11 @@ static int mergeWorkerWrite(
     ** marked read-only, advance to the next page of the output run. */
     iOff = pMerge->iOutputOff;
     if( iOff<0 || pPg==0 || iOff+nHdr > SEGMENT_EOF(nData, nRec+1) ){
+      if( iOff>=0 && pPg ){
+        /* Zero any free space on the page */
+        assert( aData );
+        memset(&aData[iOff], 0, SEGMENT_EOF(nData, nRec)-iOff);
+      }
       iFPtr = (int)*pMW->pCsr->pPrevMergePtr;
       iRPtr = iPtr - iFPtr;
       iOff = 0;
@@ -4069,36 +4074,49 @@ static void mergeWorkerShutdown(MergeWorker *pMW, int *pRc){
   /* Unless the merge has finished, save the cursor position in the
   ** Merge.aInput[] array. See function mergeWorkerInit() for the 
   ** code to restore a cursor position based on aInput[].  */
-  if( rc==LSM_OK && pCsr && lsmMCursorValid(pCsr) ){
+  if( rc==LSM_OK && pCsr ){
     Merge *pMerge = pMW->pLevel->pMerge;
-    int bBtree = (pCsr->pBtCsr!=0);
-    int iPtr;
+    if( lsmMCursorValid(pCsr) ){
+      int bBtree = (pCsr->pBtCsr!=0);
+      int iPtr;
 
-    /* pMerge->nInput==0 indicates that this is a FlushTree() operation. */
-    assert( pMerge->nInput==0 || pMW->pLevel->nRight>0 );
-    assert( pMerge->nInput==0 || pMerge->nInput==(pCsr->nPtr+bBtree) );
+      /* pMerge->nInput==0 indicates that this is a FlushTree() operation. */
+      assert( pMerge->nInput==0 || pMW->pLevel->nRight>0 );
+      assert( pMerge->nInput==0 || pMerge->nInput==(pCsr->nPtr+bBtree) );
 
-    for(i=0; i<(pMerge->nInput-bBtree); i++){
-      SegmentPtr *pPtr = &pCsr->aPtr[i];
-      if( pPtr->pPg ){
-        pMerge->aInput[i].iPg = lsmFsPageNumber(pPtr->pPg);
-        pMerge->aInput[i].iCell = pPtr->iCell;
+      for(i=0; i<(pMerge->nInput-bBtree); i++){
+        SegmentPtr *pPtr = &pCsr->aPtr[i];
+        if( pPtr->pPg ){
+          pMerge->aInput[i].iPg = lsmFsPageNumber(pPtr->pPg);
+          pMerge->aInput[i].iCell = pPtr->iCell;
+        }else{
+          pMerge->aInput[i].iPg = 0;
+          pMerge->aInput[i].iCell = 0;
+        }
+      }
+      if( bBtree && pMerge->nInput ){
+        assert( i==pCsr->nPtr );
+        btreeCursorPosition(pCsr->pBtCsr, &pMerge->aInput[i]);
+      }
+
+      /* Store the location of the split-key */
+      iPtr = pCsr->aTree[1] - CURSOR_DATA_SEGMENT;
+      if( iPtr<pCsr->nPtr ){
+        pMerge->splitkey = pMerge->aInput[iPtr];
       }else{
-        pMerge->aInput[i].iPg = 0;
-        pMerge->aInput[i].iCell = 0;
+        btreeCursorSplitkey(pCsr->pBtCsr, &pMerge->splitkey);
       }
     }
-    if( bBtree && pMerge->nInput ){
-      assert( i==pCsr->nPtr );
-      btreeCursorPosition(pCsr->pBtCsr, &pMerge->aInput[i]);
-    }
 
-    /* Store the location of the split-key */
-    iPtr = pCsr->aTree[1] - CURSOR_DATA_SEGMENT;
-    if( iPtr<pCsr->nPtr ){
-      pMerge->splitkey = pMerge->aInput[iPtr];
-    }else{
-      btreeCursorSplitkey(pCsr->pBtCsr, &pMerge->splitkey);
+    /* Zero any free space left on the final page. This helps with
+    ** compression if using a compression hook. And prevents valgrind
+    ** from complaining about uninitialized byte passed to write(). */
+    if( pMW->pPage ){
+      int nData;
+      u8 *aData = fsPageData(pMW->pPage, &nData);
+      int iOff = pMerge->iOutputOff;
+      int iEof = SEGMENT_EOF(nData, pageGetNRec(aData, nData));
+      memset(&aData[iOff], 0, iEof - iOff);
     }
     
     pMerge->iOutputOff = -1;

diff --git a/manifest b/manifest
index df822c015e0817a493e3612e0409cfb7b56f9b4f..d601661e295fb30fb8790a2983bde5bba256e80c 100644 (file)
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\sa\smissing\s"finish_test"\sto\sthe\send\sof\sthe\sstmtvtab1.test\sscript.
-D 2017-11-16T19:04:33.787
+C Ensure\sthat\sempty\sspace\son\spages\sis\szeroed\sbefore\sthey\sare\swritten\sto\sdisk.\nThis\shelps\swith\scompressed\sdatabases,\sand\sstops\svalgrind\scomplaining\sabout\nuninitialized\sbytes\sand\swrite().
+D 2017-11-16T20:48:47.980
 F Makefile.in b142eb20482922153ebc77b261cdfd0a560ed05a81e9f6d9a2b0e8192922a1d2
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc a55372a22454e742ba7c8f6edf05b83213ec01125166ad7dcee0567e2f7fc81b
@@ -246,7 +246,7 @@ F ext/lsm1/lsm_main.c 15e73ccdafdd44ddeefc29e332079d88ba8f00c12c797b3c2b63d3171b
 F ext/lsm1/lsm_mem.c 4c51ea9fa285ee6e35301b33491642d071740a0a
 F ext/lsm1/lsm_mutex.c 378edf0a2b142b4f7640ee982df06d50b98788ea
 F ext/lsm1/lsm_shared.c 76adfc1ed9ffebaf92746dde4b370ccc48143ca8b05b563816eadd2aadf1c525
-F ext/lsm1/lsm_sorted.c a04518dfbfff0171fafb152a46e9fe9f45e1edbf3570e4533dd58ddb6567f0c9
+F ext/lsm1/lsm_sorted.c 8f899fb64a4c736ff3c27d5126c7ce181129ddffde947fe5fb657a7a413f470b
 F ext/lsm1/lsm_str.c 65e361b488c87b10bf3e5c0070b14ffc602cf84f094880bece77bbf6678bca82
 F ext/lsm1/lsm_tree.c 682679d7ef2b8b6f2fe77aeb532c8d29695bca671c220b0abac77069de5fb9fb
 F ext/lsm1/lsm_unix.c 57361bcf5b1a1a028f5d66571ee490e9064d2cfb145a2cc9e5ddade467bb551b
@@ -1677,7 +1677,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 1ca3b8cce93e83fabe35c22cb726b8ce0883e0448afa3301ad0b53073055fa8d
-R 43f6376592b4d26341e49684bbb727c1
-U drh
-Z 7e47c726c44355ca56f3a93b39a4aaed
+P e0b5c0585e8530bd516b340093a46d8e358a731facb78da22d3208633c852804
+R a54da776e28f1875d13b67b86731a30b
+U dan
+Z 4bb1ae38bdfadd3dc2e110f3406150e8

diff --git a/manifest.uuid b/manifest.uuid
index 4216e3c295508634858499759dcf07d4d6911283..39825a308f1fb469d11d554489c5eeae0d3cf300 100644 (file)
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-e0b5c0585e8530bd516b340093a46d8e358a731facb78da22d3208633c852804
\ No newline at end of file
+5ffec5db33137251090d45e2ca7e3e7823e3215ae89822d905923424ceba2ac2
\ No newline at end of file