third_party/sqlite/sqlite-src-3080704/ext/misc/fileio.c

   1 /*
   2 ** 2014-06-13
   3 **
   4 ** The author disclaims copyright to this source code.  In place of
   5 ** a legal notice, here is a blessing:
   6 **
   7 **    May you do good and not evil.
   8 **    May you find forgiveness for yourself and forgive others.
   9 **    May you share freely, never taking more than you give.
  10 **
  11 ******************************************************************************
  12 **
  13 ** This SQLite extension implements SQL functions readfile() and
  14 ** writefile().
  15 */
  16 #include "sqlite3ext.h"
  17 SQLITE_EXTENSION_INIT1
  18 #include <stdio.h>
  19
  20 /*
  21 ** Implementation of the "readfile(X)" SQL function.  The entire content
  22 ** of the file named X is read and returned as a BLOB.  NULL is returned
  23 ** if the file does not exist or is unreadable.
  24 */
  25 static void readfileFunc(
  26   sqlite3_context *context,
  27   int argc,
  28   sqlite3_value **argv
  29 ){
  30   const char *zName;
  31   FILE *in;
  32   long nIn;
  33   void *pBuf;
  34
  35   zName = (const char*)sqlite3_value_text(argv[0]);
  36   if( zName==0 ) return;
  37   in = fopen(zName, "rb");
  38   if( in==0 ) return;
  39   fseek(in, 0, SEEK_END);
  40   nIn = ftell(in);
  41   rewind(in);
  42   pBuf = sqlite3_malloc( nIn );
  43   if( pBuf && 1==fread(pBuf, nIn, 1, in) ){
  44     sqlite3_result_blob(context, pBuf, nIn, sqlite3_free);
  45   }else{
  46     sqlite3_free(pBuf);
  47   }
  48   fclose(in);
  49 }
  50
  51 /*
  52 ** Implementation of the "writefile(X,Y)" SQL function.  The argument Y
  53 ** is written into file X.  The number of bytes written is returned.  Or
  54 ** NULL is returned if something goes wrong, such as being unable to open
  55 ** file X for writing.
  56 */
  57 static void writefileFunc(
  58   sqlite3_context *context,
  59   int argc,
  60   sqlite3_value **argv
  61 ){
  62   FILE *out;
  63   const char *z;
  64   sqlite3_int64 rc;
  65   const char *zFile;
  66
  67   zFile = (const char*)sqlite3_value_text(argv[0]);
  68   if( zFile==0 ) return;
  69   out = fopen(zFile, "wb");
  70   if( out==0 ) return;
  71   z = (const char*)sqlite3_value_blob(argv[1]);
  72   if( z==0 ){
  73     rc = 0;
  74   }else{
  75     rc = fwrite(z, 1, sqlite3_value_bytes(argv[1]), out);
  76   }
  77   fclose(out);
  78   sqlite3_result_int64(context, rc);
  79 }
  80
  81
  82 #ifdef _WIN32
  83 __declspec(dllexport)
  84 #endif
  85 int sqlite3_fileio_init(
  86   sqlite3 *db,
  87   char **pzErrMsg,
  88   const sqlite3_api_routines *pApi
  89 ){
  90   int rc = SQLITE_OK;
  91   SQLITE_EXTENSION_INIT2(pApi);
  92   (void)pzErrMsg;  /* Unused parameter */
  93   rc = sqlite3_create_function(db, "readfile", 1, SQLITE_UTF8, 0,
  94                                readfileFunc, 0, 0);
  95   if( rc==SQLITE_OK ){
  96     rc = sqlite3_create_function(db, "writefile", 2, SQLITE_UTF8, 0,
  97                                  writefileFunc, 0, 0);
  98   }
  99   return rc;
 100 }