cleanup: libsqfs: eliminate block writer statistics

 - the "bytes submitted" can be moved over to the block processor
 - the number of blocks submitted are already there (implcitily, by
   adding the data block count to the fragment block count)
 - actual data bytes written can be computed from the super block
 - the remaining block count can be changed to simple counter that
   can be obtained through a function.

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

5 files changed, 31 insertions, 63 deletions

diff --git a/include/sqfs/block_processor.h b/include/sqfs/block_processor.h
index be10ef0..8b50033 100644
--- a/include/sqfs/block_processor.h
+++ b/include/sqfs/block_processor.h
@@ -69,6 +69,15 @@ struct sqfs_block_processor_stats_t {
 	sqfs_u64 input_bytes_read;
 
 	/**
+	 * @brief Total number of bytes sent down to the block processor.
+	 *
+	 * This is the sum of generated, compressed blocks, including blocks
+	 * that were possibly deduplicated by the block writer and not
+	 * counting padding that the block writer may have added.
+	 */
+	sqfs_u64 output_bytes_generated;
+
+	/**
 	 * @brief Total number of data blocks produced.
 	 */
 	sqfs_u64 data_block_count;
diff --git a/include/sqfs/block_writer.h b/include/sqfs/block_writer.h
index 1fd110a..8cfb9a2 100644
--- a/include/sqfs/block_writer.h
+++ b/include/sqfs/block_writer.h
@@ -38,46 +38,6 @@
  * This object is not copyable, i.e. @ref sqfs_copy will always return NULL.
  */
 
-/**
- * @struct sqfs_block_writer_stats_t
- *
- * @brief Collects run time statistics of the @ref sqfs_block_writer_t
- */
-struct sqfs_block_writer_stats_t {
-	/**
-	 * @brief Holds the size of the structure.
-	 *
-	 * If a later version of libsquashfs expands this structure, the value
-	 * of this field can be used to check at runtime whether the newer
-	 * fields are avaialable or not.
-	 */
-	size_t size;
-
-	/**
-	 * @brief Total number of bytes submitted, including blocks that were
-	 *        removed by deduplication and not counting any padding.
-	 */
-	sqfs_u64 bytes_submitted;
-
-	/**
-	 * @brief Actual number of bytes written to disk, excluding deduplicated
-	 *        blocks and including padding.
-	 */
-	sqfs_u64 bytes_written;
-
-	/**
-	 * @brief Total number of submitted blocks, including ones later
-	 *        removed by deduplication.
-	 */
-	sqfs_u64 blocks_submitted;
-
-	/**
-	 * @brief Total number of blocks actually written, excluding
-	 *        deduplicated blocks.
-	 */
-	sqfs_u64 blocks_written;
-};
-
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -128,16 +88,16 @@ SQFS_API int sqfs_block_writer_write(sqfs_block_writer_t *wr,
 				     sqfs_u64 *location);
 
 /**
- * @brief Get access to a block writers run time statistics.
+ * @brief Get the number of blocks actually written to disk.
  *
  * @memberof sqfs_block_writer_t
  *
  * @param wr A pointer to a block writer.
  *
- * @return A pointer to the internal statistics counters.
+ * @return The number of blocks written, excluding deduplicated blocks.
  */
-SQFS_API const sqfs_block_writer_stats_t
-*sqfs_block_writer_get_stats(const sqfs_block_writer_t *wr);
+SQFS_API
+sqfs_u64 sqfs_block_writer_get_block_count(const sqfs_block_writer_t *wr);
 
 #ifdef __cplusplus
 }
diff --git a/lib/common/statistics.c b/lib/common/statistics.c
index 2f729cb..079c1b1 100644
--- a/lib/common/statistics.c
+++ b/lib/common/statistics.c
@@ -13,22 +13,23 @@ void sqfs_print_statistics(const sqfs_super_t *super,
 			   const sqfs_block_writer_t *wr)
 {
 	const sqfs_block_processor_stats_t *proc_stats;
-	const sqfs_block_writer_stats_t *wr_stats;
+	sqfs_u64 bytes_written, blocks_written;
 	char read_sz[32], written_sz[32];
 	size_t ratio;
 
 	proc_stats = sqfs_block_processor_get_stats(blk);
-	wr_stats = sqfs_block_writer_get_stats(wr);
+	blocks_written = sqfs_block_writer_get_block_count(wr);
+
+	bytes_written = super->inode_table_start - sizeof(*super);
 
 	if (proc_stats->input_bytes_read > 0) {
-		ratio = (100 * wr_stats->bytes_written) /
-			proc_stats->input_bytes_read;
+		ratio = (100 * bytes_written) / proc_stats->input_bytes_read;
 	} else {
 		ratio = 100;
 	}
 
 	print_size(proc_stats->input_bytes_read, read_sz, false);
-	print_size(wr_stats->bytes_written, written_sz, false);
+	print_size(bytes_written, written_sz, false);
 
 	fputs("---------------------------------------------------\n", stdout);
 	printf("Data bytes read: %s\n", read_sz);
@@ -36,11 +37,14 @@ void sqfs_print_statistics(const sqfs_super_t *super,
 	printf("Data compression ratio: " PRI_SZ "%%\n", ratio);
 	fputc('\n', stdout);
 
-	printf("Data blocks written: " PRI_U64 "\n", wr_stats->blocks_written);
+	printf("Data blocks written: " PRI_U64 "\n", blocks_written);
 	printf("Out of which where fragment blocks: " PRI_U64 "\n",
 	       proc_stats->frag_block_count);
+
 	printf("Duplicate blocks omitted: " PRI_U64 "\n",
-	       wr_stats->blocks_submitted - wr_stats->blocks_written);
+	       proc_stats->data_block_count + proc_stats->frag_block_count -
+	       blocks_written);
+
 	printf("Sparse blocks omitted: " PRI_U64 "\n",
 	       proc_stats->sparse_block_count);
 	fputc('\n', stdout);
diff --git a/lib/sqfs/block_processor/common.c b/lib/sqfs/block_processor/common.c
index bd37068..757544a 100644
--- a/lib/sqfs/block_processor/common.c
+++ b/lib/sqfs/block_processor/common.c
@@ -73,6 +73,8 @@ int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
 	if (err)
 		goto out;
 
+	proc->stats.output_bytes_generated += blk->size;
+
 	if (blk->flags & SQFS_BLK_IS_SPARSE) {
 		sqfs_inode_make_extended(*(blk->inode));
 		(*(blk->inode))->data.file_ext.sparse += blk->size;
diff --git a/lib/sqfs/block_writer.c b/lib/sqfs/block_writer.c
index b819b58..06cbd37 100644
--- a/lib/sqfs/block_writer.c
+++ b/lib/sqfs/block_writer.c
@@ -34,8 +34,7 @@ struct sqfs_block_writer_t {
 	blk_info_t *blocks;
 	size_t devblksz;
 
-	sqfs_block_writer_stats_t stats;
-
+	sqfs_u64 blocks_written;
 	sqfs_u64 data_area_start;
 
 	sqfs_u64 start;
@@ -132,7 +131,6 @@ sqfs_block_writer_t *sqfs_block_writer_create(sqfs_file_t *file,
 	wr->file = file;
 	wr->devblksz = devblksz;
 	wr->max_blocks = INIT_BLOCK_COUNT;
-	wr->stats.size = sizeof(wr->stats);
 	wr->data_area_start = wr->file->get_size(wr->file);
 
 	wr->blocks = alloc_array(sizeof(wr->blocks[0]), wr->max_blocks);
@@ -180,10 +178,7 @@ int sqfs_block_writer_write(sqfs_block_writer_t *wr, sqfs_u32 size,
 		if (err)
 			return err;
 
-		wr->stats.bytes_submitted += size;
-		wr->stats.blocks_submitted += 1;
-		wr->stats.blocks_written = wr->num_blocks;
-		wr->stats.bytes_written = offset + size - wr->data_area_start;
+		wr->blocks_written = wr->num_blocks;
 	}
 
 	if (flags & SQFS_BLK_LAST_BLOCK) {
@@ -218,15 +213,13 @@ int sqfs_block_writer_write(sqfs_block_writer_t *wr, sqfs_u32 size,
 				return err;
 		}
 
-		wr->stats.blocks_written = wr->num_blocks;
-		wr->stats.bytes_written = wr->start - wr->data_area_start;
+		wr->blocks_written = wr->num_blocks;
 	}
 
 	return 0;
 }
 
-const sqfs_block_writer_stats_t
-*sqfs_block_writer_get_stats(const sqfs_block_writer_t *wr)
+sqfs_u64 sqfs_block_writer_get_block_count(const sqfs_block_writer_t *wr)
 {
-	return &wr->stats;
+	return wr->blocks_written;
 }