Changeset 912

Timestamp:

01/09/2006 08:49:31 (5 years ago)

Author:

chris

Message:

(refs #3)

Use truncation/sparse files to quickly create files with 200MB of zeroes

File:

• box/chris/merge/test/backupdiff/testbackupdiff.cpp (modified) (1 diff)

box/chris/merge/test/backupdiff/testbackupdiff.cpp

@@ -67 +67 @@
 void make_file_of_zeros(const char *filename, size_t size)
 {
-        static const size_t bs = 0x10000;
-        size_t remSize = size;
-        void *b = malloc(bs);
-        memset(b, 0, bs);
-        FILE *f = fopen(filename, "wb");
-
-        // Using largish blocks like this is much faster, while not consuming too much RAM
-        while(remSize > bs)
-        {
-                fwrite(b, bs, 1, f);
-                remSize -= bs;
-        }
-        fwrite(b, remSize, 1, f);
-
-        fclose(f);
-        free(b);
+        #ifdef WIN32
+        HANDLE handle = openfile(filename, O_WRONLY | O_CREAT | O_EXCL, 0);
+        TEST_THAT(handle != INVALID_HANDLE_VALUE);
+        SetFilePointer(handle, size, NULL, FILE_BEGIN);
+        TEST_THAT(GetLastError() == NO_ERROR);
+        TEST_THAT(SetEndOfFile(handle) == true);
+        TEST_THAT(CloseHandle(handle)  == true);
+        #else
+        int fd = open(filename, O_WRONLY | O_CREAT | O_EXCL, 0600);
+        if (fd < 0) perror(filename);
+        TEST_THAT(fd >= 0);
+        TEST_THAT(ftruncate(fd, size) == 0);
+        TEST_THAT(close(fd) == 0);
+        #endif
 
         TEST_THAT((size_t)TestGetFileSize(filename) == size);