Move block block accounting to the other end of the block pipeline

This commit moves all of the fragment/block accounting in the block
processor over to the writing end of the pipeline. In order to do
this, the sparse blocks are allowed to bubble through the pipeline.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>

4 files changed, 26 insertions, 23 deletions

diff --git a/include/sqfs/block.h b/include/sqfs/block.h
index 30fcc1d..b4860ac 100644
--- a/include/sqfs/block.h
+++ b/include/sqfs/block.h
@@ -89,6 +89,12 @@ typedef enum {
 	SQFS_BLK_DONT_FRAGMENT = 0x0004,
 
 	/**
+	 * @brief Set by the @ref sqfs_block_processor_t if it determines a
+	 *        block of a file to be sparse, i.e. only zero bytes.
+	 */
+	SQFS_BLK_IS_SPARSE = 0x0400,
+
+	/**
 	 * @brief Set by the @ref sqfs_block_processor_t on the first
 	 *        block of a file.
 	 */
diff --git a/lib/sqfs/block_processor/common.c b/lib/sqfs/block_processor/common.c
index c8dbbc2..002dad4 100644
--- a/lib/sqfs/block_processor/common.c
+++ b/lib/sqfs/block_processor/common.c
@@ -13,6 +13,16 @@ int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
 	sqfs_u32 size;
 	int err;
 
+	if (blk->flags & SQFS_BLK_IS_SPARSE) {
+		sqfs_inode_make_extended(blk->inode);
+		blk->inode->data.file_ext.sparse += blk->size;
+		blk->inode->extra[blk->inode->num_file_blocks] = 0;
+		blk->inode->num_file_blocks += 1;
+
+		proc->stats.sparse_block_count += 1;
+		return 0;
+	}
+
 	size = blk->size;
 	if (!(blk->flags & SQFS_BLK_IS_COMPRESSED))
 		size |= 1 << 24;
@@ -29,7 +39,10 @@ int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
 			if (err)
 				return err;
 		} else {
-			blk->inode->extra[blk->index] = size;
+			blk->inode->extra[blk->inode->num_file_blocks] = size;
+			blk->inode->num_file_blocks += 1;
+
+			proc->stats.data_block_count += 1;
 		}
 	}
 
@@ -44,7 +57,7 @@ int block_processor_do_block(sqfs_block_t *block, sqfs_compressor_t *cmp,
 {
 	ssize_t ret;
 
-	if (block->size == 0) {
+	if (block->size == 0 || (block->flags & SQFS_BLK_IS_SPARSE)) {
 		block->checksum = 0;
 		return 0;
 	}
@@ -77,6 +90,8 @@ int process_completed_fragment(sqfs_block_processor_t *proc, sqfs_block_t *frag,
 	size_t size;
 	int err;
 
+	proc->stats.total_frag_count += 1;
+
 	err = sqfs_frag_table_find_tail_end(proc->frag_tbl,
 					    frag->checksum, frag->size,
 					    &index, &offset);
diff --git a/lib/sqfs/block_processor/fileapi.c b/lib/sqfs/block_processor/fileapi.c
index dbe3cf2..7ca189e 100644
--- a/lib/sqfs/block_processor/fileapi.c
+++ b/lib/sqfs/block_processor/fileapi.c
@@ -49,38 +49,22 @@ int sqfs_block_processor_begin_file(sqfs_block_processor_t *proc,
 
 	proc->inode = inode;
 	proc->blk_flags = flags | SQFS_BLK_FIRST_BLOCK;
-	proc->blk_index = 0;
 	proc->blk_current = NULL;
 	return 0;
 }
 
 static int flush_block(sqfs_block_processor_t *proc, sqfs_block_t *block)
 {
-	block->index = proc->blk_index++;
 	block->flags = proc->blk_flags;
 	block->inode = proc->inode;
 
 	if (is_zero_block(block->data, block->size)) {
-		sqfs_inode_make_extended(proc->inode);
-		proc->inode->data.file_ext.sparse += block->size;
-		proc->inode->num_file_blocks += 1;
-		proc->inode->extra[block->index] = 0;
-		free(block);
-
-		proc->stats.sparse_block_count += 1;
-		return 0;
-	}
-
-	if (block->size < proc->max_block_size &&
-	    !(block->flags & SQFS_BLK_DONT_FRAGMENT)) {
+		block->flags |= SQFS_BLK_IS_SPARSE;
+	} else if (block->size < proc->max_block_size &&
+		   !(block->flags & SQFS_BLK_DONT_FRAGMENT)) {
 		block->flags |= SQFS_BLK_IS_FRAGMENT;
-
-		proc->stats.total_frag_count += 1;
 	} else {
-		proc->inode->num_file_blocks += 1;
 		proc->blk_flags &= ~SQFS_BLK_FIRST_BLOCK;
-
-		proc->stats.data_block_count += 1;
 	}
 
 	return enqueue_block(proc, block);
@@ -162,6 +146,5 @@ int sqfs_block_processor_end_file(sqfs_block_processor_t *proc)
 
 	proc->inode = NULL;
 	proc->blk_flags = 0;
-	proc->blk_index = 0;
 	return 0;
 }
diff --git a/lib/sqfs/block_processor/internal.h b/lib/sqfs/block_processor/internal.h
index 45db014..cea820f 100644
--- a/lib/sqfs/block_processor/internal.h
+++ b/lib/sqfs/block_processor/internal.h
@@ -90,7 +90,6 @@ struct sqfs_block_processor_t {
 	sqfs_inode_generic_t *inode;
 	sqfs_block_t *blk_current;
 	sqfs_u32 blk_flags;
-	size_t blk_index;
 
 	/* used only by workers */
 	size_t max_block_size;