[sql] Import reference version of SQLite 3.17..

third_party/sqlite/sqlite-src-3170000/ext/rbu/rbu.c

+/*
+** 2014 August 30
+**
+** The author disclaims copyright to this source code.  In place of
+** a legal notice, here is a blessing:
+**
+**    May you do good and not evil.
+**    May you find forgiveness for yourself and forgive others.
+**    May you share freely, never taking more than you give.
+**
+*************************************************************************
+**
+** This file contains a command-line application that uses the RBU 
+** extension. See the usage() function below for an explanation.
+*/
+
+#include "sqlite3rbu.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+/*
+** Print a usage message and exit.
+*/
+void usage(const char *zArgv0){
+  fprintf(stderr, 
+"Usage: %s ?OPTIONS? TARGET-DB RBU-DB\n"
+"\n"
+"Where options are:\n"
+"\n"
+"    -step NSTEP\n"
+"    -vacuum\n"
+"\n"
+"  If the -vacuum switch is not present, argument RBU-DB must be an RBU\n"
+"  database containing an update suitable for target database TARGET-DB.\n"
+"  Or, if -vacuum is specified, then TARGET-DB is a database to vacuum using\n"
+"  RBU, and RBU-DB is used as the state database for the vacuum (refer to\n"
+"  API documentation for details).\n"
+"\n"
+"  If NSTEP is set to less than or equal to zero (the default value), this \n"
+"  program attempts to perform the entire update or vacuum operation before\n"
+"  exiting\n"
+"\n"
+"  If NSTEP is greater than zero, then a maximum of NSTEP calls are made\n"
+"  to sqlite3rbu_step(). If the RBU update has not been completely applied\n"
+"  after the NSTEP'th call is made, the state is saved in the database RBU-DB\n"
+"  and the program exits. Subsequent invocations of this (or any other RBU)\n"
+"  application will use this state to resume applying the RBU update to the\n"
+"  target db.\n"
+"\n"
+, zArgv0);
+  exit(1);
+}
+
+void report_default_vfs(){
+  sqlite3_vfs *pVfs = sqlite3_vfs_find(0);
+  fprintf(stdout, "default vfs is \"%s\"\n", pVfs->zName);
+}
+
+void report_rbu_vfs(sqlite3rbu *pRbu){
+  sqlite3 *db = sqlite3rbu_db(pRbu, 0);
+  if( db ){
+    char *zName = 0;
+    sqlite3_file_control(db, "main", SQLITE_FCNTL_VFSNAME, &zName);
+    if( zName ){
+      fprintf(stdout, "using vfs \"%s\"\n", zName);
+    }else{
+      fprintf(stdout, "vfs name not available\n");
+    }
+    sqlite3_free(zName);
+  }
+}
+
+int main(int argc, char **argv){
+  int i;
+  const char *zTarget;            /* Target database to apply RBU to */
+  const char *zRbu;               /* Database containing RBU */
+  char zBuf[200];                 /* Buffer for printf() */
+  char *zErrmsg;                  /* Error message, if any */
+  sqlite3rbu *pRbu;               /* RBU handle */
+  int nStep = 0;                  /* Maximum number of step() calls */
+  int bVacuum = 0;
+  int rc;
+  sqlite3_int64 nProgress = 0;
+  int nArg = argc-2;
+
+  if( argc<3 ) usage(argv[0]);
+  for(i=1; i<nArg; i++){
+    const char *zArg = argv[i];
+    int nArg = strlen(zArg);
+    if( nArg>1 && nArg<=8 && 0==memcmp(zArg, "-vacuum", nArg) ){
+      bVacuum = 1;
+    }else if( nArg>1 && nArg<=5 && 0==memcmp(zArg, "-step", nArg) && i<nArg-1 ){
+      i++;
+      nStep = atoi(argv[i]);
+    }else{
+      usage(argv[0]);
+    }
+  }
+
+  zTarget = argv[argc-2];
+  zRbu = argv[argc-1];
+
+  report_default_vfs();
+
+  /* Open an RBU handle. A vacuum handle if -vacuum was specified, or a
+  ** regular RBU update handle otherwise.  */
+  if( bVacuum ){
+    pRbu = sqlite3rbu_vacuum(zTarget, zRbu);
+  }else{
+    pRbu = sqlite3rbu_open(zTarget, zRbu, 0);
+  }
+  report_rbu_vfs(pRbu);
+
+  /* If nStep is less than or equal to zero, call
+  ** sqlite3rbu_step() until either the RBU has been completely applied
+  ** or an error occurs. Or, if nStep is greater than zero, call
+  ** sqlite3rbu_step() a maximum of nStep times.  */
+  for(i=0; (nStep<=0 || i<nStep) && sqlite3rbu_step(pRbu)==SQLITE_OK; i++);
+  nProgress = sqlite3rbu_progress(pRbu);
+  rc = sqlite3rbu_close(pRbu, &zErrmsg);
+
+  /* Let the user know what happened. */
+  switch( rc ){
+    case SQLITE_OK:
+      sqlite3_snprintf(sizeof(zBuf), zBuf,
+          "SQLITE_OK: rbu update incomplete (%lld operations so far)\n",
+          nProgress
+      );
+      fprintf(stdout, "%s", zBuf);
+      break;
+
+    case SQLITE_DONE:
+      sqlite3_snprintf(sizeof(zBuf), zBuf,
+          "SQLITE_DONE: rbu update completed (%lld operations)\n",
+          nProgress
+      );
+      fprintf(stdout, "%s", zBuf);
+      break;
+
+    default:
+      fprintf(stderr, "error=%d: %s\n", rc, zErrmsg);
+      break;
+  }
+
+  sqlite3_free(zErrmsg);
+  return (rc==SQLITE_OK || rc==SQLITE_DONE) ? 0 : 1;
+}