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Performance improvements on memory copies inside of btree by moving 2 bytes 

at a time instead of just 1 byte at a time.

FossilOrigin-Name: 897f56a158ebe62758c9998e4941ae046c75fb99
This commit is contained in:
drh 2011-06-03 23:28:33 +00:00
parent 3a61a5a2b5
commit 61d2fe955c
3 changed files with 17 additions and 14 deletions
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12
manifest
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@ -1,5 +1,5 @@
C Performance\senhancement\sto\sthe\sblob-literal\stokenizer.
D 2011-06-03T21:34:45.326
C Performance\simprovements\son\smemory\scopies\sinside\sof\sbtree\sby\smoving\s2\sbytes\nat\sa\stime\sinstead\sof\sjust\s1\sbyte\sat\sa\stime.
D 2011-06-03T23:28:33.011
F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@ -122,7 +122,7 @@ F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
F src/backup.c 986c15232757f2873dff35ee3b35cbf935fc573c
F src/bitvec.c af50f1c8c0ff54d6bdb7a80e2fceca5a93670bef
F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
F src/btree.c 12aa3b71359c888984223cb2bcf691cf2d7753ae
F src/btree.c 9f214af284fae1e96f12989dcc4d26f247b502fc
F src/btree.h f5d775cd6cfc7ac32a2535b70e8d2af48ef5f2ce
F src/btreeInt.h 67978c014fa4f7cc874032dd3aacadd8db656bc3
F src/build.c 5a428625d21ad409514afb40ad083bee25dd957a
@ -942,7 +942,7 @@ F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
F tool/symbols.sh bc2a3709940d47c8ac8e0a1fdf17ec801f015a00
F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
F tool/warnings.sh 347d974d143cf132f953b565fbc03026f19fcb4d
P 957b2ab67c6185f0e1062593d237de5c434a38bf
R bd36ddd3c30f1348cf18f2599b20bbca
P 61aa2031f1c5ae05e31077588a55194a9546262a
R ee8453a74951d0e43529f6f62862f77e
U drh
Z fe6a860af7a1658c61a1531782a69559
Z eb5472e3af1761c7727508ef6d936f22

2
manifest.uuid
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@ -1 +1 @@
61aa2031f1c5ae05e31077588a55194a9546262a
897f56a158ebe62758c9998e4941ae046c75fb99

17
src/btree.c
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@ -5422,8 +5422,7 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
}
endPtr = &data[pPage->cellOffset + 2*pPage->nCell - 2];
while( ptr<endPtr ){
ptr[0] = ptr[2];
ptr[1] = ptr[3];
*(u16*)ptr = *(u16*)&ptr[2];
ptr += 2;
}
pPage->nCell--;
@ -5464,6 +5463,7 @@ static void insertCell(
int cellOffset; /* Address of first cell pointer in data[] */
u8 *data; /* The content of the whole page */
u8 *ptr; /* Used for moving information around in data[] */
u8 *endPtr; /* End of the loop */
int nSkip = (iChild ? 4 : 0);
@ -5514,9 +5514,11 @@ static void insertCell(
if( iChild ){
put4byte(&data[idx], iChild);
}
for(j=end, ptr=&data[j]; j>ins; j-=2, ptr-=2){
ptr[0] = ptr[-2];
ptr[1] = ptr[-1];
ptr = &data[end];
endPtr = &data[ins];
while( ptr>endPtr ){
*(u16*)ptr = *(u16*)&ptr[-2];
ptr -= 2;
}
put2byte(&data[ins], idx);
put2byte(&data[pPage->hdrOffset+3], pPage->nCell);
@ -5561,10 +5563,11 @@ static void assemblePage(
pCellptr = &data[pPage->cellOffset + nCell*2];
cellbody = nUsable;
for(i=nCell-1; i>=0; i--){
u16 sz = aSize[i];
pCellptr -= 2;
cellbody -= aSize[i];
cellbody -= sz;
put2byte(pCellptr, cellbody);
memcpy(&data[cellbody], apCell[i], aSize[i]);
memcpy(&data[cellbody], apCell[i], sz);
}
put2byte(&data[hdr+3], nCell);
put2byte(&data[hdr+5], cellbody);