X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=bluesky%2Ffile.c;h=19363756b17e3fc32ede50a6c4b2f4faa539909a;hb=9dfe082624e7eea541e2ccff9e638e8d7fbdcbf2;hp=f10814ab40e40b9f7cf286437536a377e5231a6f;hpb=5d183280ac0033ad534af598fea85fd802e14ffe;p=bluesky.git diff --git a/bluesky/file.c b/bluesky/file.c index f10814a..1936375 100644 --- a/bluesky/file.c +++ b/bluesky/file.c @@ -77,6 +77,15 @@ void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size) uint64_t blocks = (size + BLUESKY_BLOCK_SIZE - 1) / BLUESKY_BLOCK_SIZE; + /* Calculate number of bytes in the last block of the file */ + int lastblock_old, lastblock_new; + lastblock_old = inode->size % BLUESKY_BLOCK_SIZE; + if (lastblock_old == 0 && inode->size > 0) + lastblock_old = BLUESKY_BLOCK_SIZE; + lastblock_new = size % BLUESKY_BLOCK_SIZE; + if (lastblock_new == 0 && size > 0) + lastblock_new = BLUESKY_BLOCK_SIZE; + if (blocks > inode->blocks->len) { /* Need to add new blocks to the end of a file. New block structures * are automatically zeroed, which initializes them to be pointers to @@ -88,10 +97,14 @@ void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size) inode->blocks->len - 1); if (b->type != BLUESKY_BLOCK_ZERO - && (b->type == BLUESKY_BLOCK_REF - || b->dirty->len < BLUESKY_BLOCK_SIZE)) { + && lastblock_old < BLUESKY_BLOCK_SIZE) { bluesky_block_touch(inode, inode->blocks->len - 1, TRUE); gsize old_size = b->dirty->len; + if (lastblock_old != old_size) { + fprintf(stderr, + "Warning: last block size = %zd, expected %d\n", + old_size, lastblock_old); + } bluesky_string_resize(b->dirty, BLUESKY_BLOCK_SIZE); memset(&b->dirty->data[old_size], 0, BLUESKY_BLOCK_SIZE - old_size); @@ -117,7 +130,13 @@ void bluesky_file_truncate(BlueSkyInode *inode, uint64_t size) BlueSkyBlock *b = &g_array_index(inode->blocks, BlueSkyBlock, blocks - 1); - if (b->type != BLUESKY_BLOCK_ZERO) { + gboolean need_resize = TRUE; + if (b->type == BLUESKY_BLOCK_ZERO) + need_resize = FALSE; + else if (size < inode->size && lastblock_new == BLUESKY_BLOCK_SIZE) + need_resize = FALSE; + + if (need_resize) { bluesky_block_touch(inode, blocks - 1, TRUE); gsize old_size = b->dirty->len; gsize new_size = size - (blocks - 1) * BLUESKY_BLOCK_SIZE; @@ -144,16 +163,17 @@ void bluesky_file_write(BlueSkyInode *inode, uint64_t offset, if (len == 0) return; - // TODO: Optimization: If we are entirely overwriting a block we don't need - // to fetch it frm storage first. We don't yet handle the case where the - // partial last block of a file is entirely overwritten. while (len > 0) { uint64_t block_num = offset / BLUESKY_BLOCK_SIZE; gint block_offset = offset % BLUESKY_BLOCK_SIZE; gint bytes = MIN(BLUESKY_BLOCK_SIZE - block_offset, len); gboolean preserve = TRUE; - if (block_offset == 0 && bytes == BLUESKY_BLOCK_SIZE) { + gsize block_size = BLUESKY_BLOCK_SIZE; + if (block_num == inode->blocks->len - 1) { + block_size = inode->size - block_num * BLUESKY_BLOCK_SIZE; + } + if (block_offset == 0 && bytes == block_size) { preserve = FALSE; } bluesky_block_touch(inode, block_num, preserve);