Revert of "[sql] Remove part of WebDatabase SQLite patch." (patchset #1 of https://codereview.chrom…

third_party/sqlite/src/src/os_unix.c

 /*
 ** 2004 May 22
 **
 ** 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.
 **
@@ skipping 5626 matching lines @@
                                                int fd,
                                                int dirfd,
                                                sqlite3_file* file,
                                                const char* fileName,
                                                int noLock) {
   int ctrlFlags = (noLock ? UNIXFILE_NOLOCK : 0);
   return fillInUnixFile(vfs, fd, file, fileName, ctrlFlags);
 }
 
 /*
+** Search for an unused file descriptor that was opened on the database file.
+** If a suitable file descriptor if found, then it is stored in *fd; otherwise,
+** *fd is not modified.
+**
+** If a reusable file descriptor is not found, and a new UnixUnusedFd cannot
+** be allocated, SQLITE_NOMEM is returned. Otherwise, SQLITE_OK is returned.
+*/
+CHROMIUM_SQLITE_API
+int chromium_sqlite3_get_reusable_file_handle(sqlite3_file* file,
+                                              const char* fileName,
+                                              int flags,
+                                              int* fd) {
+  unixFile* unixSQLite3File = (unixFile*)file;
+  int fileType = flags & 0xFFFFFF00;
+  if (fileType == SQLITE_OPEN_MAIN_DB) {
+    UnixUnusedFd *unusedFd = findReusableFd(fileName, flags);
+    if (unusedFd) {
+      *fd = unusedFd->fd;
+    } else {
+      unusedFd = sqlite3_malloc(sizeof(*unusedFd));
+      if (!unusedFd) {
+        return SQLITE_NOMEM;
+      }
+    }
+    unixSQLite3File->pUnused = unusedFd;
+  }
+  return SQLITE_OK;
+}
+
+/*
 ** Marks 'fd' as the unused file descriptor for 'pFile'.
 */
 CHROMIUM_SQLITE_API
 void chromium_sqlite3_update_reusable_file_handle(sqlite3_file* file,
                                                   int fd,
                                                   int flags) {
   unixFile* unixSQLite3File = (unixFile*)file;
   if (unixSQLite3File->pUnused) {
     unixSQLite3File->pUnused->fd = fd;
     unixSQLite3File->pUnused->flags = flags;
@@ skipping 106 matching lines @@
   ** are harmless.
   */
   if( randomnessPid!=getpid() ){
     randomnessPid = getpid();
     sqlite3_randomness(0,0);
   }
 
   chromium_sqlite3_initialize_unix_sqlite3_file(pFile);
 
   if( eType==SQLITE_OPEN_MAIN_DB ){
-    UnixUnusedFd *pUnused;
-    pUnused = findReusableFd(zName, flags);
-    if( pUnused ){
-      fd = pUnused->fd;
-    }else{
-      pUnused = sqlite3_malloc(sizeof(*pUnused));
-      if( !pUnused ){
-        return SQLITE_NOMEM;
-      }
+    rc = chromium_sqlite3_get_reusable_file_handle(pFile, zName, flags, &fd);
+    if( rc!=SQLITE_OK ){
+      return rc;
     }
-    p->pUnused = pUnused;
 
     /* Database filenames are double-zero terminated if they are not
     ** URIs with parameters.  Hence, they can always be passed into
     ** sqlite3_uri_parameter(). */
     assert( (flags & SQLITE_OPEN_URI) || zName[strlen(zName)+1]==0 );
 
   }else if( !zName ){
     /* If zName is NULL, the upper layer is requesting a temp file. */
     assert(isDelete && !syncDir);
     rc = unixGetTempname(MAX_PATHNAME+2, zTmpname);
@@ skipping 1778 matching lines @@
 **
 ** Some operating systems might need to do some cleanup in this routine,
 ** to release dynamically allocated objects.  But not on unix.
 ** This routine is a no-op for unix.
 */
 int sqlite3_os_end(void){ 
   return SQLITE_OK; 
 }
  
 #endif /* SQLITE_OS_UNIX */