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Overview
Comment: | Add the write-ahead log viewer/debugger tool to the tools/ folder. |
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Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | trunk |
Files: | files | file ages | folders |
SHA1: |
0e4bd44682a252fb8af0df20f011b2b2 |
User & Date: | drh 2010-07-07 20:38:26.000 |
Context
2010-07-07
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21:06 | Make the initial salt values in the WAL header random values, not zero. (check-in: baa5eddd05 user: drh tags: trunk) | |
20:38 | Add the write-ahead log viewer/debugger tool to the tools/ folder. (check-in: 0e4bd44682 user: drh tags: trunk) | |
20:00 | Fix issue in mallocI test script where db handle not released. (check-in: dd59cea6c8 user: shaneh tags: trunk) | |
Changes
Added tool/showwal.c.
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Return the number of bytes ** in the var-int. Write the var-int value into *pVal. */ static int decodeVarint(const unsigned char *z, i64 *pVal){ i64 v = 0; int i; for(i=0; i<8; i++){ v = (v<<7) + (z[i]&0x7f); if( (z[i]&0x80)==0 ){ *pVal = v; return i+1; } } v = (v<<8) + (z[i]&0xff); *pVal = v; return 9; } /* Report an out-of-memory error and die. */ static void out_of_memory(void){ fprintf(stderr,"Out of memory...\n"); exit(1); } /* ** Read content from the file. ** ** Space to hold the content is obtained from malloc() and needs to be ** freed by the caller. */ static unsigned char *getContent(int ofst, int nByte){ unsigned char *aData; aData = malloc(nByte); if( aData==0 ) out_of_memory(); lseek(fd, ofst, SEEK_SET); read(fd, aData, nByte); return aData; } /* ** Print a range of bytes as hex and as ascii. */ static void print_byte_range( int ofst, /* First byte in the range of bytes to print */ int nByte, /* Number of bytes to print */ unsigned char *aData, /* Content to print */ int printOfst /* Add this amount to the index on the left column */ ){ int i, j; const char *zOfstFmt; if( ((printOfst+nByte)&~0xfff)==0 ){ zOfstFmt = " %03x: "; }else if( ((printOfst+nByte)&~0xffff)==0 ){ zOfstFmt = " %04x: "; }else if( ((printOfst+nByte)&~0xfffff)==0 ){ zOfstFmt = " %05x: "; }else if( ((printOfst+nByte)&~0xffffff)==0 ){ zOfstFmt = " %06x: "; }else{ zOfstFmt = " %08x: "; } for(i=0; i<nByte; i += perLine){ fprintf(stdout, zOfstFmt, i+printOfst); for(j=0; j<perLine; j++){ if( i+j>nByte ){ fprintf(stdout, " "); }else{ fprintf(stdout,"%02x ", aData[i+j]); } } for(j=0; j<perLine; j++){ if( i+j>nByte ){ fprintf(stdout, " "); }else{ fprintf(stdout,"%c", isprint(aData[i+j]) ? aData[i+j] : '.'); } } fprintf(stdout,"\n"); } } /* Print a line of decode output showing a 4-byte integer. */ static void print_decode_line( unsigned char *aData, /* Content being decoded */ int ofst, int nByte, /* Start and size of decode */ int asHex, /* If true, output value as hex */ const char *zMsg /* Message to append */ ){ int i, j; int val = aData[ofst]; char zBuf[100]; sprintf(zBuf, " %03x: %02x", ofst, aData[ofst]); i = strlen(zBuf); for(j=1; j<4; j++){ if( j>=nByte ){ sprintf(&zBuf[i], " "); }else{ sprintf(&zBuf[i], " %02x", aData[ofst+j]); val = val*256 + aData[ofst+j]; } i += strlen(&zBuf[i]); } if( asHex ){ sprintf(&zBuf[i], " 0x%08x", val); }else{ sprintf(&zBuf[i], " %9d", val); } printf("%s %s\n", zBuf, zMsg); } /* ** Print an entire page of content as hex */ static void print_frame(int iFrame){ int iStart; unsigned char *aData; iStart = 32 + (iFrame-1)*(pagesize+24); fprintf(stdout, "Frame %d: (offsets 0x%x..0x%x)\n", iFrame, iStart, iStart+pagesize+24); aData = getContent(iStart, pagesize+24); print_decode_line(aData, 0, 4, 0, "Page number"); print_decode_line(aData, 4, 4, 0, "DB size, or 0 for non-commit"); print_decode_line(aData, 8, 4, 1, "Salt-1"); print_decode_line(aData,12, 4, 1, "Salt-2"); print_decode_line(aData,16, 4, 1, "Checksum-1"); print_decode_line(aData,20, 4, 1, "Checksum-2"); print_byte_range(iStart+24, pagesize, aData+24, 0); free(aData); } /* ** extract a 32-bit big-endian integer */ static unsigned int getInt32(const unsigned char *a){ unsigned int x = (a[0]<<24) + (a[1]<<16) + (a[2]<<8) + a[3]; return x; } /* ** Print an entire page of content as hex */ static void print_oneline_frame(int iFrame){ int iStart; unsigned char *aData; iStart = 32 + (iFrame-1)*(pagesize+24); aData = getContent(iStart, 24); fprintf(stdout, "Frame %4d: %6d %6d 0x%08x 0x%08x 0x%08x 0x%08x\n", iFrame, getInt32(aData), getInt32(aData+4), getInt32(aData+8), getInt32(aData+12), getInt32(aData+16), getInt32(aData+20) ); free(aData); } /* ** Decode the WAL header. */ static void print_wal_header(void){ unsigned char *aData; aData = getContent(0, 32); printf("WAL Header:\n"); print_decode_line(aData, 0, 4,1,"Magic. 0x377f0682 (le) or 0x377f0683 (be)"); print_decode_line(aData, 4, 4, 0, "File format"); print_decode_line(aData, 8, 4, 0, "Database page size"); print_decode_line(aData, 12,4, 0, "Checkpoint sequence number"); print_decode_line(aData, 16,4, 1, "Salt-1"); print_decode_line(aData, 20,4, 1, "Salt-2"); print_decode_line(aData, 24,4, 1, "Checksum-1"); print_decode_line(aData, 28,4, 1, "Checksum-2"); free(aData); } /* ** Create a description for a single cell. */ static int describeCell(unsigned char cType, unsigned char *a, char **pzDesc){ int i; int nDesc = 0; int n = 0; int leftChild; i64 nPayload; i64 rowid; static char zDesc[100]; i = 0; if( cType<=5 ){ leftChild = ((a[0]*256 + a[1])*256 + a[2])*256 + a[3]; a += 4; n += 4; sprintf(zDesc, "left-child: %d ", leftChild); nDesc = strlen(zDesc); } if( cType!=5 ){ i = decodeVarint(a, &nPayload); a += i; n += i; sprintf(&zDesc[nDesc], "sz: %lld ", nPayload); nDesc += strlen(&zDesc[nDesc]); } if( cType==5 || cType==13 ){ i = decodeVarint(a, &rowid); a += i; n += i; sprintf(&zDesc[nDesc], "rowid: %lld ", rowid); nDesc += strlen(&zDesc[nDesc]); } *pzDesc = zDesc; return n; } /* ** Decode a btree page */ static void decode_btree_page(unsigned char *a, int pgno, int hdrSize){ const char *zType = "unknown"; int nCell; int i; int iCellPtr; switch( a[0] ){ case 2: zType = "index interior node"; break; case 5: zType = "table interior node"; break; case 10: zType = "index leaf"; break; case 13: zType = "table leaf"; break; } printf("Decode of btree page %d:\n", pgno); print_decode_line(a, 0, 1, 0, zType); print_decode_line(a, 1, 2, 0, "Offset to first freeblock"); print_decode_line(a, 3, 2, 0, "Number of cells on this page"); nCell = a[3]*256 + a[4]; print_decode_line(a, 5, 2, 0, "Offset to cell content area"); print_decode_line(a, 7, 1, 0, "Fragmented byte count"); if( a[0]==2 || a[0]==5 ){ print_decode_line(a, 8, 4, 0, "Right child"); iCellPtr = 12; }else{ iCellPtr = 8; } for(i=0; i<nCell; i++){ int cofst = iCellPtr + i*2; char *zDesc; cofst = a[cofst]*256 + a[cofst+1]; describeCell(a[0], &a[cofst-hdrSize], &zDesc); printf(" %03x: cell[%d] %s\n", cofst, i, zDesc); } } int main(int argc, char **argv){ struct stat sbuf; unsigned char zPgSz[2]; if( argc<2 ){ fprintf(stderr,"Usage: %s FILENAME ?PAGE? ...\n", argv[0]); exit(1); } fd = open(argv[1], O_RDONLY); if( fd<0 ){ fprintf(stderr,"%s: can't open %s\n", argv[0], argv[1]); exit(1); } zPgSz[0] = 0; zPgSz[1] = 0; lseek(fd, 10, SEEK_SET); read(fd, zPgSz, 2); pagesize = zPgSz[0]*256 + zPgSz[1]; if( pagesize==0 ) pagesize = 1024; printf("Pagesize: %d\n", pagesize); fstat(fd, &sbuf); if( sbuf.st_size<32 ){ printf("file too small to be a WAL\n"); return 0; } mxFrame = (sbuf.st_size - 32)/(pagesize + 24); printf("Available pages: 1..%d\n", mxFrame); if( argc==2 ){ int i; print_wal_header(); for(i=1; i<=mxFrame; i++) print_oneline_frame(i); }else{ int i; for(i=2; i<argc; i++){ int iStart, iEnd; char *zLeft; if( strcmp(argv[i], "header")==0 ){ print_wal_header(); continue; } if( !isdigit(argv[i][0]) ){ fprintf(stderr, "%s: unknown option: [%s]\n", argv[0], argv[i]); continue; } iStart = strtol(argv[i], &zLeft, 0); if( zLeft && strcmp(zLeft,"..end")==0 ){ iEnd = mxFrame; }else if( zLeft && zLeft[0]=='.' && zLeft[1]=='.' ){ iEnd = strtol(&zLeft[2], 0, 0); #if 0 }else if( zLeft && zLeft[0]=='b' ){ int ofst, nByte, hdrSize; unsigned char *a; if( iStart==1 ){ ofst = hdrSize = 100; nByte = pagesize-100; }else{ hdrSize = 0; ofst = (iStart-1)*pagesize; nByte = pagesize; } a = getContent(ofst, nByte); decode_btree_page(a, iStart, hdrSize); free(a); continue; #endif }else{ iEnd = iStart; } if( iStart<1 || iEnd<iStart || iEnd>mxFrame ){ fprintf(stderr, "Page argument should be LOWER?..UPPER?. Range 1 to %d\n", mxFrame); exit(1); } while( iStart<=iEnd ){ print_frame(iStart); iStart++; } } } close(fd); return 0; } |