Imported from /home/lorry/working-area/delta_berkeleydb/db-6.1.23.tar.gz.HEADdb-6.1.23master

1 files changed, 312 insertions, 6 deletions

diff --git a/lang/sql/sqlite/tool/showdb.c b/lang/sql/sqlite/tool/showdb.c
index c954153c..4d274a7a 100644
--- a/lang/sql/sqlite/tool/showdb.c
+++ b/lang/sql/sqlite/tool/showdb.c
@@ -6,9 +6,14 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
+
+#if !defined(_MSC_VER)
 #include <unistd.h>
+#endif
+
 #include <stdlib.h>
 #include <string.h>
+#include "sqlite3.h"
 
 
 static int pagesize = 1024;     /* Size of a database page */
@@ -114,7 +119,7 @@ static unsigned char *print_byte_range(
 /*
 ** Print an entire page of content as hex
 */
-static print_page(int iPg){
+static void print_page(int iPg){
   int iStart;
   unsigned char *aData;
   iStart = (iPg-1)*pagesize;
@@ -126,7 +131,7 @@ static print_page(int iPg){
 
 /* Print a line of decode output showing a 4-byte integer.
 */
-static print_decode_line(
+static void print_decode_line(
   unsigned char *aData,      /* Content being decoded */
   int ofst, int nByte,       /* Start and size of decode */
   const char *zMsg           /* Message to append */
@@ -171,7 +176,7 @@ static void print_db_header(void){
   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, 68, 4, "Application ID");
   print_decode_line(aData, 72, 4, "meta[8]");
   print_decode_line(aData, 76, 4, "meta[9]");
   print_decode_line(aData, 80, 4, "meta[10]");
@@ -423,7 +428,7 @@ static void decode_trunk_page(
   int detail,           /* Show leaf pages if true */
   int recursive         /* Follow the trunk change if true */
 ){
-  int n, i, k;
+  int n, i;
   unsigned char *a;
   while( pgno>0 ){
     a = getContent((pgno-1)*pagesize, pagesize);
@@ -451,6 +456,293 @@ static void decode_trunk_page(
 }
 
 /*
+** A short text comment on the use of each page.
+*/
+static char **zPageUse;
+
+/*
+** Add a comment on the use of a page.
+*/
+static void page_usage_msg(int pgno, const char *zFormat, ...){
+  va_list ap;
+  char *zMsg;
+
+  va_start(ap, zFormat);
+  zMsg = sqlite3_vmprintf(zFormat, ap);
+  va_end(ap);
+  if( pgno<=0 || pgno>mxPage ){
+    printf("ERROR: page %d out of range 1..%d: %s\n",
+            pgno, mxPage, zMsg);
+    sqlite3_free(zMsg);
+    return;
+  }
+  if( zPageUse[pgno]!=0 ){
+    printf("ERROR: page %d used multiple times:\n", pgno);
+    printf("ERROR:    previous: %s\n", zPageUse[pgno]);
+    printf("ERROR:    current:  %s\n", zMsg);
+    sqlite3_free(zPageUse[pgno]);
+  }
+  zPageUse[pgno] = zMsg;
+}
+
+/*
+** Find overflow pages of a cell and describe their usage.
+*/
+static void page_usage_cell(
+  unsigned char cType,    /* Page type */
+  unsigned char *a,       /* Cell content */
+  int pgno,               /* page containing the cell */
+  int cellno              /* Index of the cell on the page */
+){
+  int i;
+  int n = 0;
+  i64 nPayload;
+  i64 rowid;
+  int nLocal;
+  i = 0;
+  if( cType<=5 ){
+    a += 4;
+    n += 4;
+  }
+  if( cType!=5 ){
+    i = decodeVarint(a, &nPayload);
+    a += i;
+    n += i;
+    nLocal = localPayload(nPayload, cType);
+  }else{
+    nPayload = nLocal = 0;
+  }
+  if( cType==5 || cType==13 ){
+    i = decodeVarint(a, &rowid);
+    a += i;
+    n += i;
+  }
+  if( nLocal<nPayload ){
+    int ovfl = decodeInt32(a+nLocal);
+    int cnt = 0;
+    while( ovfl && (cnt++)<mxPage ){
+      page_usage_msg(ovfl, "overflow %d from cell %d of page %d",
+                     cnt, cellno, pgno);
+      a = getContent((ovfl-1)*pagesize, 4);
+      ovfl = decodeInt32(a);
+      free(a);
+    }
+  }
+}
+
+
+/*
+** Describe the usages of a b-tree page
+*/
+static void page_usage_btree(
+  int pgno,             /* Page to describe */
+  int parent,           /* Parent of this page.  0 for root pages */
+  int idx,              /* Which child of the parent */
+  const char *zName     /* Name of the table */
+){
+  unsigned char *a;
+  const char *zType = "corrupt node";
+  int nCell;
+  int i;
+  int hdr = pgno==1 ? 100 : 0;
+
+  if( pgno<=0 || pgno>mxPage ) return;
+  a = getContent((pgno-1)*pagesize, pagesize);
+  switch( a[hdr] ){
+    case 2:  zType = "interior node of index";  break;
+    case 5:  zType = "interior node of table";  break;
+    case 10: zType = "leaf of index";           break;
+    case 13: zType = "leaf of table";           break;
+  }
+  if( parent ){
+    page_usage_msg(pgno, "%s [%s], child %d of page %d",
+                   zType, zName, idx, parent);
+  }else{
+    page_usage_msg(pgno, "root %s [%s]", zType, zName);
+  }
+  nCell = a[hdr+3]*256 + a[hdr+4];
+  if( a[hdr]==2 || a[hdr]==5 ){
+    int cellstart = hdr+12;
+    unsigned int child;
+    for(i=0; i<nCell; i++){
+      int ofst;
+
+      ofst = cellstart + i*2;
+      ofst = a[ofst]*256 + a[ofst+1];
+      child = decodeInt32(a+ofst);
+      page_usage_btree(child, pgno, i, zName);
+    }
+    child = decodeInt32(a+cellstart-4);
+    page_usage_btree(child, pgno, i, zName);
+  }
+  if( a[hdr]==2 || a[hdr]==10 || a[hdr]==13 ){
+    int cellstart = hdr + 8 + 4*(a[hdr]<=5);
+    for(i=0; i<nCell; i++){
+      int ofst;
+      ofst = cellstart + i*2;
+      ofst = a[ofst]*256 + a[ofst+1];
+      page_usage_cell(a[hdr], a+ofst, pgno, i);
+    }
+  }
+  free(a);
+}
+
+/*
+** Determine page usage by the freelist
+*/
+static void page_usage_freelist(int pgno){
+  unsigned char *a;
+  int cnt = 0;
+  int i;
+  int n;
+  int iNext;
+  int parent = 1;
+
+  while( pgno>0 && pgno<=mxPage && (cnt++)<mxPage ){
+    page_usage_msg(pgno, "freelist trunk #%d child of %d", cnt, parent);
+    a = getContent((pgno-1)*pagesize, pagesize);
+    iNext = decodeInt32(a);
+    n = decodeInt32(a+4);
+    for(i=0; i<n; i++){
+      int child = decodeInt32(a + (i*4+8));
+      page_usage_msg(child, "freelist leaf, child %d of trunk page %d",
+                     i, pgno);
+    }
+    free(a);
+    parent = pgno;
+    pgno = iNext;
+  }
+}
+
+/*
+** Determine pages used as PTRMAP pages
+*/
+static void page_usage_ptrmap(unsigned char *a){
+  if( a[55] ){
+    int usable = pagesize - a[20];
+    int pgno = 2;
+    int perPage = usable/5;
+    while( pgno<=mxPage ){
+      page_usage_msg(pgno, "PTRMAP page covering %d..%d",
+                           pgno+1, pgno+perPage);
+      pgno += perPage + 1;
+    }
+  }
+}
+
+/*
+** Try to figure out how every page in the database file is being used.
+*/
+static void page_usage_report(const char *zDbName){
+  int i, j;
+  int rc;
+  sqlite3 *db;
+  sqlite3_stmt *pStmt;
+  unsigned char *a;
+  char zQuery[200];
+
+  /* Avoid the pathological case */
+  if( mxPage<1 ){
+    printf("empty database\n");
+    return;
+  }
+
+  /* Open the database file */
+  rc = sqlite3_open(zDbName, &db);
+  if( rc ){
+    printf("cannot open database: %s\n", sqlite3_errmsg(db));
+    sqlite3_close(db);
+    return;
+  }
+
+  /* Set up global variables zPageUse[] and mxPage to record page
+  ** usages */
+  zPageUse = sqlite3_malloc( sizeof(zPageUse[0])*(mxPage+1) );
+  if( zPageUse==0 ) out_of_memory();
+  memset(zPageUse, 0, sizeof(zPageUse[0])*(mxPage+1));
+
+  /* Discover the usage of each page */
+  a = getContent(0, 100);
+  page_usage_freelist(decodeInt32(a+32));
+  page_usage_ptrmap(a);
+  free(a);
+  page_usage_btree(1, 0, 0, "sqlite_master");
+  sqlite3_exec(db, "PRAGMA writable_schema=ON", 0, 0, 0);
+  for(j=0; j<2; j++){
+    sqlite3_snprintf(sizeof(zQuery), zQuery,
+             "SELECT type, name, rootpage FROM SQLITE_MASTER WHERE rootpage"
+             " ORDER BY rowid %s", j?"DESC":"");
+    rc = sqlite3_prepare_v2(db, zQuery, -1, &pStmt, 0);
+    if( rc==SQLITE_OK ){
+      while( sqlite3_step(pStmt)==SQLITE_ROW ){
+        int pgno = sqlite3_column_int(pStmt, 2);
+        page_usage_btree(pgno, 0, 0, (const char*)sqlite3_column_text(pStmt,1));
+      }
+    }else{
+      printf("ERROR: cannot query database: %s\n", sqlite3_errmsg(db));
+    }
+    rc = sqlite3_finalize(pStmt);
+    if( rc==SQLITE_OK ) break;
+  }
+  sqlite3_close(db);
+
+  /* Print the report and free memory used */
+  for(i=1; i<=mxPage; i++){
+    printf("%5d: %s\n", i, zPageUse[i] ? zPageUse[i] : "???");
+    sqlite3_free(zPageUse[i]);
+  }
+  sqlite3_free(zPageUse);
+  zPageUse = 0;
+}
+
+/*
+** Try to figure out how every page in the database file is being used.
+*/
+static void ptrmap_coverage_report(const char *zDbName){
+  unsigned int pgno;
+  unsigned char *aHdr;
+  unsigned char *a;
+  int usable;
+  int perPage;
+  unsigned int i;
+
+  /* Avoid the pathological case */
+  if( mxPage<1 ){
+    printf("empty database\n");
+    return;
+  }
+
+  /* Make sure PTRMAPs are used in this database */
+  aHdr = getContent(0, 100);
+  if( aHdr[55]==0 ){
+    printf("database does not use PTRMAP pages\n");
+    return;
+  }
+  usable = pagesize - aHdr[20];
+  perPage = usable/5;
+  free(aHdr);
+  printf("%5d: root of sqlite_master\n", 1);
+  for(pgno=2; pgno<=mxPage; pgno += perPage+1){
+    printf("%5d: PTRMAP page covering %d..%d\n", pgno,
+           pgno+1, pgno+perPage);
+    a = getContent((pgno-1)*pagesize, usable);
+    for(i=0; i+5<=usable && pgno+1+i/5<=mxPage; i+=5){
+      const char *zType = "???";
+      unsigned int iFrom = decodeInt32(&a[i+1]);
+      switch( a[i] ){
+        case 1:  zType = "b-tree root page";        break;
+        case 2:  zType = "freelist page";           break;
+        case 3:  zType = "first page of overflow";  break;
+        case 4:  zType = "later page of overflow";  break;
+        case 5:  zType = "b-tree non-root page";    break;
+      }
+      printf("%5d: %s, parent=%u\n", pgno+1+i/5, zType, iFrom);
+    }
+    free(a);
+  }
+}
+
+/*
 ** Print a usage comment
 */
 static void usage(const char *argv0){
@@ -458,13 +750,15 @@ static void usage(const char *argv0){
   fprintf(stderr,
     "args:\n"
     "    dbheader        Show database header\n"
+    "    pgidx           Index of how each page is used\n"
+    "    ptrmap          Show all PTRMAP page content\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"
+    "    NNNtd           Show leaf freelist pages on the decode\n"
     "    NNNtr           Recurisvely decode freelist starting at NNN\n"
   );
 }
@@ -503,6 +797,18 @@ int main(int argc, char **argv){
         print_db_header();
         continue;
       }
+      if( strcmp(argv[i], "pgidx")==0 ){
+        page_usage_report(argv[1]);
+        continue;
+      }
+      if( strcmp(argv[i], "ptrmap")==0 ){
+        ptrmap_coverage_report(argv[1]);
+        continue;
+      }
+      if( strcmp(argv[i], "help")==0 ){
+        usage(argv[0]);
+        continue;
+      }
       if( !isdigit(argv[i][0]) ){
         fprintf(stderr, "%s: unknown option: [%s]\n", argv[0], argv[i]);
         continue;
@@ -528,7 +834,6 @@ int main(int argc, char **argv){
         free(a);
         continue;
       }else if( zLeft && zLeft[0]=='t' ){
-        unsigned char *a;
         int detail = 0;
         int recursive = 0;
         int i;
@@ -554,4 +859,5 @@ int main(int argc, char **argv){
     }
   }
   close(db);
+  return 0;
 }