Import SQLite 3.7.6.3.

third_party/sqlite/src/tool/showdb.c

 /*
 ** A utility for printing all or part of an SQLite database file.
 */
 #include <stdio.h>
 #include <ctype.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <unistd.h>
 #include <stdlib.h>
-
-
-static int pagesize = 1024;
-static int db = -1;
-static int mxPage = 0;
-static int perLine = 32;
-
+#include <string.h>
+
+
+static int pagesize = 1024;     /* Size of a database page */
+static int db = -1;             /* File descriptor for reading the DB */
+static int mxPage = 0;          /* Last page number */
+static int perLine = 16;        /* HEX elements to print per line */
+
+typedef long long int i64;      /* Datatype for 64-bit integers */
+
+
+/*
+** Convert the var-int format into i64.  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;
+}
+
+/*
+** Extract a big-endian 32-bit integer
+*/
+static unsigned int decodeInt32(const unsigned char *z){
+  return (z[0]<<24) + (z[1]<<16) + (z[2]<<8) + z[3];
+}
+
+/* Report an out-of-memory error and die.
+*/
 static void out_of_memory(void){
   fprintf(stderr,"Out of memory...\n");
   exit(1);
 }
 
-static print_page(int iPg){
+/*
+** 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+32);
+  if( aData==0 ) out_of_memory();
+  memset(aData, 0, nByte+32);
+  lseek(db, ofst, SEEK_SET);
+  read(db, aData, nByte);
+  return aData;
+}
+
+/*
+** Print a range of bytes as hex and as ascii.
+*/
+static unsigned char *print_byte_range(
+  int ofst,          /* First byte in the range of bytes to print */
+  int nByte,         /* Number of bytes to print */
+  int printOfst      /* Add this amount to the index on the left column */
+){
   unsigned char *aData;
   int i, j;
-  aData = malloc(pagesize);
-  if( aData==0 ) out_of_memory();
-  lseek(db, (iPg-1)*(long long int)pagesize, SEEK_SET);
-  read(db, aData, pagesize);
-  fprintf(stdout, "Page %d:\n", iPg);
-  for(i=0; i<pagesize; i += perLine){
-    fprintf(stdout, " %03x: ",i);
+  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: ";
+  }
+
+  aData = getContent(ofst, nByte);
+  for(i=0; i<nByte; i += perLine){
+    fprintf(stdout, zOfstFmt, i+printOfst);
     for(j=0; j<perLine; j++){
-      fprintf(stdout,"%02x ", aData[i+j]);
+      if( i+j>nByte ){
+        fprintf(stdout, "   ");
+      }else{
+        fprintf(stdout,"%02x ", aData[i+j]);
+      }
     }
     for(j=0; j<perLine; j++){
-      fprintf(stdout,"%c", isprint(aData[i+j]) ? aData[i+j] : '.');
+      if( i+j>nByte ){
+        fprintf(stdout, " ");
+      }else{
+        fprintf(stdout,"%c", isprint(aData[i+j]) ? aData[i+j] : '.');
+      }
     }
     fprintf(stdout,"\n");
   }
+  return aData;
+}
+
+/*
+** Print an entire page of content as hex
+*/
+static print_page(int iPg){
+  int iStart;
+  unsigned char *aData;
+  iStart = (iPg-1)*pagesize;
+  fprintf(stdout, "Page %d:   (offsets 0x%x..0x%x)\n",
+          iPg, iStart, iStart+pagesize-1);
+  aData = print_byte_range(iStart, pagesize, 0);
   free(aData);
 }
 
+/* Print a line of decode output showing a 4-byte integer.
+*/
+static print_decode_line(
+  unsigned char *aData,      /* Content being decoded */
+  int ofst, int nByte,       /* Start and size of decode */
+  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]);
+  }
+  sprintf(&zBuf[i], "   %9d", val);
+  printf("%s  %s\n", zBuf, zMsg);
+}
+
+/*
+** Decode the database header.
+*/
+static void print_db_header(void){
+  unsigned char *aData;
+  aData = print_byte_range(0, 100, 0);
+  printf("Decoded:\n");
+  print_decode_line(aData, 16, 2, "Database page size");
+  print_decode_line(aData, 18, 1, "File format write version");
+  print_decode_line(aData, 19, 1, "File format read version");
+  print_decode_line(aData, 20, 1, "Reserved space at end of page");
+  print_decode_line(aData, 24, 4, "File change counter");
+  print_decode_line(aData, 28, 4, "Size of database in pages");
+  print_decode_line(aData, 32, 4, "Page number of first freelist page");
+  print_decode_line(aData, 36, 4, "Number of freelist pages");
+  print_decode_line(aData, 40, 4, "Schema cookie");
+  print_decode_line(aData, 44, 4, "Schema format version");
+  print_decode_line(aData, 48, 4, "Default page cache size");
+  print_decode_line(aData, 52, 4, "Largest auto-vac root page");
+  print_decode_line(aData, 56, 4, "Text encoding");
+  print_decode_line(aData, 60, 4, "User version");
+  print_decode_line(aData, 64, 4, "Incremental-vacuum mode");
+  print_decode_line(aData, 68, 4, "meta[7]");
+  print_decode_line(aData, 72, 4, "meta[8]");
+  print_decode_line(aData, 76, 4, "meta[9]");
+  print_decode_line(aData, 80, 4, "meta[10]");
+  print_decode_line(aData, 84, 4, "meta[11]");
+  print_decode_line(aData, 88, 4, "meta[12]");
+  print_decode_line(aData, 92, 4, "Change counter for version number");
+  print_decode_line(aData, 96, 4, "SQLite version number");
+}
+
+/*
+** Describe cell content.
+*/
+static int describeContent(
+  unsigned char *a,       /* Cell content */
+  int nLocal,             /* Bytes in a[] */
+  char *zDesc             /* Write description here */
+){
+  int nDesc = 0;
+  int n, i, j;
+  i64 x, v;
+  const unsigned char *pData;
+  const unsigned char *pLimit;
+  char sep = ' ';
+
+  pLimit = &a[nLocal];
+  n = decodeVarint(a, &x);
+  pData = &a[x];
+  a += n;
+  i = x - n;
+  while( i>0 && pData<=pLimit ){
+    n = decodeVarint(a, &x);
+    a += n;
+    i -= n;
+    nLocal -= n;
+    zDesc[0] = sep;
+    sep = ',';
+    nDesc++;
+    zDesc++;
+    if( x==0 ){
+      sprintf(zDesc, "*");     /* NULL is a "*" */
+    }else if( x>=1 && x<=6 ){
+      v = (signed char)pData[0];
+      pData++;
+      switch( x ){
+        case 6:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
+        case 5:  v = (v<<16) + (pData[0]<<8) + pData[1];  pData += 2;
+        case 4:  v = (v<<8) + pData[0];  pData++;
+        case 3:  v = (v<<8) + pData[0];  pData++;
+        case 2:  v = (v<<8) + pData[0];  pData++;
+      }
+      sprintf(zDesc, "%lld", v);
+    }else if( x==7 ){
+      sprintf(zDesc, "real");
+      pData += 8;
+    }else if( x==8 ){
+      sprintf(zDesc, "0");
+    }else if( x==9 ){
+      sprintf(zDesc, "1");
+    }else if( x>=12 ){
+      int size = (x-12)/2;
+      if( (x&1)==0 ){
+        sprintf(zDesc, "blob(%d)", size);
+      }else{
+        sprintf(zDesc, "txt(%d)", size);
+      }
+      pData += size;
+    }
+    j = strlen(zDesc);
+    zDesc += j;
+    nDesc += j;
+  }
+  return nDesc;
+}
+
+/*
+** Compute the local payload size given the total payload size and
+** the page size.
+*/
+static int localPayload(i64 nPayload, char cType){
+  int maxLocal;
+  int minLocal;
+  int surplus;
+  int nLocal;
+  if( cType==13 ){
+    /* Table leaf */
+    maxLocal = pagesize-35;
+    minLocal = (pagesize-12)*32/255-23;
+  }else{
+    maxLocal = (pagesize-12)*64/255-23;
+    minLocal = (pagesize-12)*32/255-23;
+  }
+  if( nPayload>maxLocal ){
+    surplus = minLocal + (nPayload-minLocal)%(pagesize-4);
+    if( surplus<=maxLocal ){
+      nLocal = surplus;
+    }else{
+      nLocal = minLocal;
+    }
+  }else{
+    nLocal = nPayload;
+  }
+  return nLocal;
+}
+  
+
+/*
+** Create a description for a single cell.
+**
+** The return value is the local cell size.
+*/
+static int describeCell(
+  unsigned char cType,    /* Page type */
+  unsigned char *a,       /* Cell content */
+  int showCellContent,    /* Show cell content if true */
+  char **pzDesc           /* Store description here */
+){
+  int i;
+  int nDesc = 0;
+  int n = 0;
+  int leftChild;
+  i64 nPayload;
+  i64 rowid;
+  int nLocal;
+  static char zDesc[1000];
+  i = 0;
+  if( cType<=5 ){
+    leftChild = ((a[0]*256 + a[1])*256 + a[2])*256 + a[3];
+    a += 4;
+    n += 4;
+    sprintf(zDesc, "lx: %d ", leftChild);
+    nDesc = strlen(zDesc);
+  }
+  if( cType!=5 ){
+    i = decodeVarint(a, &nPayload);
+    a += i;
+    n += i;
+    sprintf(&zDesc[nDesc], "n: %lld ", nPayload);
+    nDesc += strlen(&zDesc[nDesc]);
+    nLocal = localPayload(nPayload, cType);
+  }else{
+    nPayload = nLocal = 0;
+  }
+  if( cType==5 || cType==13 ){
+    i = decodeVarint(a, &rowid);
+    a += i;
+    n += i;
+    sprintf(&zDesc[nDesc], "r: %lld ", rowid);
+    nDesc += strlen(&zDesc[nDesc]);
+  }
+  if( nLocal<nPayload ){
+    int ovfl;
+    unsigned char *b = &a[nLocal];
+    ovfl = ((b[0]*256 + b[1])*256 + b[2])*256 + b[3];
+    sprintf(&zDesc[nDesc], "ov: %d ", ovfl);
+    nDesc += strlen(&zDesc[nDesc]);
+    n += 4;
+  }
+  if( showCellContent && cType!=5 ){
+    nDesc += describeContent(a, nLocal, &zDesc[nDesc-1]);
+  }
+  *pzDesc = zDesc;
+  return nLocal+n;
+}
+
+/*
+** Decode a btree page
+*/
+static void decode_btree_page(
+  unsigned char *a,   /* Page content */
+  int pgno,           /* Page number */
+  int hdrSize,        /* Size of the page header.  0 or 100 */
+  char *zArgs         /* Flags to control formatting */
+){
+  const char *zType = "unknown";
+  int nCell;
+  int i, j;
+  int iCellPtr;
+  int showCellContent = 0;
+  int showMap = 0;
+  char *zMap = 0;
+  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;
+  }
+  while( zArgs[0] ){
+    switch( zArgs[0] ){
+      case 'c': showCellContent = 1;  break;
+      case 'm': showMap = 1;          break;
+    }
+    zArgs++;
+  }
+  printf("Decode of btree page %d:\n", pgno);
+  print_decode_line(a, 0, 1, zType);
+  print_decode_line(a, 1, 2, "Offset to first freeblock");
+  print_decode_line(a, 3, 2, "Number of cells on this page");
+  nCell = a[3]*256 + a[4];
+  print_decode_line(a, 5, 2, "Offset to cell content area");
+  print_decode_line(a, 7, 1, "Fragmented byte count");
+  if( a[0]==2 || a[0]==5 ){
+    print_decode_line(a, 8, 4, "Right child");
+    iCellPtr = 12;
+  }else{
+    iCellPtr = 8;
+  }
+  if( nCell>0 ){
+    printf(" key: lx=left-child n=payload-size r=rowid\n");
+  }
+  if( showMap ){
+    zMap = malloc(pagesize);
+    memset(zMap, '.', pagesize);
+    memset(zMap, '1', hdrSize);
+    memset(&zMap[hdrSize], 'H', iCellPtr);
+    memset(&zMap[hdrSize+iCellPtr], 'P', 2*nCell);
+  }
+  for(i=0; i<nCell; i++){
+    int cofst = iCellPtr + i*2;
+    char *zDesc;
+    int n;
+
+    cofst = a[cofst]*256 + a[cofst+1];
+    n = describeCell(a[0], &a[cofst-hdrSize], showCellContent, &zDesc);
+    if( showMap ){
+      char zBuf[30];
+      memset(&zMap[cofst], '*', n);
+      zMap[cofst] = '[';
+      zMap[cofst+n-1] = ']';
+      sprintf(zBuf, "%d", i);
+      j = strlen(zBuf);
+      if( j<=n-2 ) memcpy(&zMap[cofst+1], zBuf, j);
+    }
+    printf(" %03x: cell[%d] %s\n", cofst, i, zDesc);
+  }
+  if( showMap ){
+    for(i=0; i<pagesize; i+=64){
+      printf(" %03x: %.64s\n", i, &zMap[i]);
+    }
+    free(zMap);
+  }  
+}
+
+/*
+** Decode a freelist trunk page.
+*/
+static void decode_trunk_page(
+  int pgno,             /* The page number */
+  int pagesize,         /* Size of each page */
+  int detail,           /* Show leaf pages if true */
+  int recursive         /* Follow the trunk change if true */
+){
+  int n, i, k;
+  unsigned char *a;
+  while( pgno>0 ){
+    a = getContent((pgno-1)*pagesize, pagesize);
+    printf("Decode of freelist trunk page %d:\n", pgno);
+    print_decode_line(a, 0, 4, "Next freelist trunk page");
+    print_decode_line(a, 4, 4, "Number of entries on this page");
+    if( detail ){
+      n = (int)decodeInt32(&a[4]);
+      for(i=0; i<n; i++){
+        unsigned int x = decodeInt32(&a[8+4*i]);
+        char zIdx[10];
+        sprintf(zIdx, "[%d]", i);
+        printf("  %5s %7u", zIdx, x);
+        if( i%5==4 ) printf("\n");
+      }
+      if( i%5!=0 ) printf("\n");
+    }
+    if( !recursive ){
+      pgno = 0;
+    }else{
+      pgno = (int)decodeInt32(&a[0]);
+    }
+    free(a);
+  }
+}
+
+/*
+** Print a usage comment
+*/
+static void usage(const char *argv0){
+  fprintf(stderr, "Usage %s FILENAME ?args...?\n\n", argv0);
+  fprintf(stderr,
+    "args:\n"
+    "    dbheader        Show database header\n"
+    "    NNN..MMM        Show hex of pages NNN through MMM\n"
+    "    NNN..end        Show hex of pages NNN through end of file\n"
+    "    NNNb            Decode btree page NNN\n"
+    "    NNNbc           Decode btree page NNN and show content\n"
+    "    NNNbm           Decode btree page NNN and show a layout map\n"
+    "    NNNt            Decode freelist trunk page NNN\n"
+    "    NNNtd           Show leave freelist pages on the decode\n"
+    "    NNNtr           Recurisvely decode freelist starting at NNN\n"
+  );
+}
+
 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]);
+    usage(argv[0]);
     exit(1);
   }
   db = open(argv[1], O_RDONLY);
   if( db<0 ){
     fprintf(stderr,"%s: can't open %s\n", argv[0], argv[1]);
     exit(1);
   }
+  zPgSz[0] = 0;
+  zPgSz[1] = 0;
+  lseek(db, 16, SEEK_SET);
+  read(db, zPgSz, 2);
+  pagesize = zPgSz[0]*256 + zPgSz[1]*65536;
+  if( pagesize==0 ) pagesize = 1024;
+  printf("Pagesize: %d\n", pagesize);
   fstat(db, &sbuf);
-  mxPage = sbuf.st_size/pagesize + 1;
+  mxPage = sbuf.st_size/pagesize;
+  printf("Available pages: 1..%d\n", mxPage);
   if( argc==2 ){
     int i;
     for(i=1; i<=mxPage; i++) print_page(i);
   }else{
     int i;
     for(i=2; i<argc; i++){
       int iStart, iEnd;
       char *zLeft;
+      if( strcmp(argv[i], "dbheader")==0 ){
+        print_db_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 = mxPage;
       }else if( zLeft && zLeft[0]=='.' && zLeft[1]=='.' ){
         iEnd = strtol(&zLeft[2], 0, 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, &zLeft[1]);
+        free(a);
+        continue;
+      }else if( zLeft && zLeft[0]=='t' ){
+        unsigned char *a;
+        int detail = 0;
+        int recursive = 0;
+        int i;
+        for(i=1; zLeft[i]; i++){
+          if( zLeft[i]=='r' ) recursive = 1;
+          if( zLeft[i]=='d' ) detail = 1;
+        }
+        decode_trunk_page(iStart, pagesize, detail, recursive);
+        continue;
       }else{
         iEnd = iStart;
       }
       if( iStart<1 || iEnd<iStart || iEnd>mxPage ){
         fprintf(stderr,
           "Page argument should be LOWER?..UPPER?.  Range 1 to %d\n",
           mxPage);
         exit(1);
       }
       while( iStart<=iEnd ){
         print_page(iStart);
         iStart++;
       }
     }
   }
   close(db);
 }