Integrate the data reader into libsquashfs

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

3 files changed, 1 insertions, 376 deletions

diff --git a/lib/sqfshelper/Makemodule.am b/lib/sqfshelper/Makemodule.am
index d711cf2..b85e6a5 100644
--- a/lib/sqfshelper/Makemodule.am
+++ b/lib/sqfshelper/Makemodule.am
@@ -6,7 +6,6 @@ libsqfshelper_a_SOURCES += lib/sqfshelper/print_version.c
 libsqfshelper_a_SOURCES += lib/sqfshelper/inode_stat.c
 libsqfshelper_a_SOURCES += lib/sqfshelper/data_reader_dump.c
 libsqfshelper_a_SOURCES += lib/sqfshelper/compress.c lib/sqfshelper/comp_opt.c
-libsqfshelper_a_SOURCES += include/data_reader.h lib/sqfshelper/data_reader.c
 libsqfshelper_a_SOURCES += include/data_writer.h lib/sqfshelper/data_writer.c
 libsqfshelper_a_SOURCES += lib/sqfshelper/write_xattr.c include/highlevel.h
 libsqfshelper_a_SOURCES += lib/sqfshelper/get_path.c
diff --git a/lib/sqfshelper/data_reader.c b/lib/sqfshelper/data_reader.c
deleted file mode 100644
index bf808ba..0000000
--- a/lib/sqfshelper/data_reader.c
+++ /dev/null
@@ -1,374 +0,0 @@
-/* SPDX-License-Identifier: GPL-3.0-or-later */
-/*
- * data_reader.c
- *
- * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
- */
-#include "config.h"
-
-#include "sqfs/block_processor.h"
-#include "sqfs/error.h"
-
-#include "data_reader.h"
-#include "highlevel.h"
-#include "util.h"
-
-#include <stdlib.h>
-#include <unistd.h>
-#include <string.h>
-#include <stdio.h>
-
-struct sqfs_data_reader_t {
-	sqfs_fragment_t *frag;
-	sqfs_compressor_t *cmp;
-	sqfs_block_t *data_block;
-	sqfs_block_t *frag_block;
-
-	uint64_t current_block;
-
-	sqfs_file_t *file;
-
-	uint32_t num_fragments;
-	uint32_t current_frag_index;
-	uint32_t block_size;
-
-	uint8_t scratch[];
-};
-
-static int get_block(sqfs_data_reader_t *data, uint64_t off, uint32_t size,
-		     size_t unpacked_size, sqfs_block_t **out)
-{
-	sqfs_block_t *blk = alloc_flex(sizeof(*blk), 1, unpacked_size);
-	size_t on_disk_size;
-	ssize_t ret;
-	int err;
-
-	if (blk == NULL)
-		return SQFS_ERROR_ALLOC;
-
-	blk->size = unpacked_size;
-
-	if (SQFS_IS_SPARSE_BLOCK(size)) {
-		*out = blk;
-		return 0;
-	}
-
-	on_disk_size = SQFS_ON_DISK_BLOCK_SIZE(size);
-
-	if (on_disk_size > unpacked_size)
-		return SQFS_ERROR_OVERFLOW;
-
-	if (SQFS_IS_BLOCK_COMPRESSED(size)) {
-		err = data->file->read_at(data->file, off,
-					  data->scratch, on_disk_size);
-		if (err) {
-			free(blk);
-			return err;
-		}
-
-		ret = data->cmp->do_block(data->cmp, data->scratch,
-					  on_disk_size, blk->data, blk->size);
-		if (ret <= 0)
-			err = ret < 0 ? ret : SQFS_ERROR_OVERFLOW;
-	} else {
-		err = data->file->read_at(data->file, off,
-					  blk->data, on_disk_size);
-	}
-
-	if (err) {
-		free(blk);
-		return err;
-	}
-
-	*out = blk;
-	return 0;
-}
-
-static int precache_data_block(sqfs_data_reader_t *data, uint64_t location,
-			       uint32_t size)
-{
-	int ret;
-
-	if (data->data_block != NULL && data->current_block == location)
-		return 0;
-
-	free(data->data_block);
-
-	ret = get_block(data, location, size, data->block_size,
-			&data->data_block);
-
-	if (ret < 0) {
-		data->data_block = NULL;
-		return -1;
-	}
-
-	data->current_block = location;
-	return 0;
-}
-
-static int precache_fragment_block(sqfs_data_reader_t *data, size_t idx)
-{
-	int ret;
-
-	if (data->frag_block != NULL && idx == data->current_frag_index)
-		return 0;
-
-	if (idx >= data->num_fragments) {
-		fputs("fragment index out of bounds\n", stderr);
-		return -1;
-	}
-
-	free(data->frag_block);
-
-	ret = get_block(data, data->frag[idx].start_offset,
-			data->frag[idx].size, data->block_size,
-			&data->frag_block);
-	if (ret < 0)
-		return -1;
-
-	data->current_frag_index = idx;
-	return 0;
-}
-
-sqfs_data_reader_t *sqfs_data_reader_create(sqfs_file_t *file,
-					    size_t block_size,
-					    sqfs_compressor_t *cmp)
-{
-	sqfs_data_reader_t *data = alloc_flex(sizeof(*data), 1, block_size);
-
-	if (data != NULL) {
-		data->file = file;
-		data->block_size = block_size;
-		data->cmp = cmp;
-	}
-
-	return data;
-}
-
-int sqfs_data_reader_load_fragment_table(sqfs_data_reader_t *data,
-					 const sqfs_super_t *super)
-{
-	void *raw_frag;
-	size_t size;
-	uint32_t i;
-	int ret;
-
-	free(data->frag_block);
-	free(data->frag);
-
-	data->frag = NULL;
-	data->frag_block = NULL;
-	data->num_fragments = 0;
-	data->current_frag_index = 0;
-
-	if (super->fragment_entry_count == 0 ||
-	    (super->flags & SQFS_FLAG_NO_FRAGMENTS) != 0) {
-		return 0;
-	}
-
-	if (super->fragment_table_start >= super->bytes_used)
-		return SQFS_ERROR_OUT_OF_BOUNDS;
-
-	if (SZ_MUL_OV(sizeof(data->frag[0]), super->fragment_entry_count,
-		      &size)) {
-		return SQFS_ERROR_OVERFLOW;
-	}
-
-	ret = sqfs_read_table(data->file, data->cmp, size,
-			      super->fragment_table_start,
-			      super->directory_table_start,
-			      super->fragment_table_start, &raw_frag);
-	if (ret)
-		return ret;
-
-	data->num_fragments = super->fragment_entry_count;
-	data->current_frag_index = super->fragment_entry_count;
-	data->frag = raw_frag;
-
-	for (i = 0; i < data->num_fragments; ++i) {
-		data->frag[i].size = le32toh(data->frag[i].size);
-		data->frag[i].start_offset =
-			le64toh(data->frag[i].start_offset);
-	}
-
-	return 0;
-}
-
-void sqfs_data_reader_destroy(sqfs_data_reader_t *data)
-{
-	free(data->data_block);
-	free(data->frag_block);
-	free(data->frag);
-	free(data);
-}
-
-int sqfs_data_reader_get_block(sqfs_data_reader_t *data,
-			       const sqfs_inode_generic_t *inode,
-			       size_t index, sqfs_block_t **out)
-{
-	size_t i, unpacked_size;
-	uint64_t off, filesz;
-
-	if (inode->base.type == SQFS_INODE_FILE) {
-		off = inode->data.file.blocks_start;
-		filesz = inode->data.file.file_size;
-	} else if (inode->base.type == SQFS_INODE_EXT_FILE) {
-		off = inode->data.file_ext.blocks_start;
-		filesz = inode->data.file_ext.file_size;
-	} else {
-		return SQFS_ERROR_NOT_FILE;
-	}
-
-	if (index >= inode->num_file_blocks)
-		return SQFS_ERROR_OUT_OF_BOUNDS;
-
-	for (i = 0; i < index; ++i) {
-		off += SQFS_ON_DISK_BLOCK_SIZE(inode->block_sizes[i]);
-		filesz -= data->block_size;
-	}
-
-	unpacked_size = filesz < data->block_size ? filesz : data->block_size;
-
-	return get_block(data, off, inode->block_sizes[index],
-			 unpacked_size, out);
-}
-
-int sqfs_data_reader_get_fragment(sqfs_data_reader_t *data,
-				  const sqfs_inode_generic_t *inode,
-				  sqfs_block_t **out)
-{
-	uint32_t frag_idx, frag_off, frag_sz;
-	sqfs_block_t *blk;
-	uint64_t filesz;
-
-	if (inode->base.type == SQFS_INODE_EXT_FILE) {
-		filesz = inode->data.file_ext.file_size;
-		frag_idx = inode->data.file_ext.fragment_idx;
-		frag_off = inode->data.file_ext.fragment_offset;
-	} else if (inode->base.type == SQFS_INODE_FILE) {
-		filesz = inode->data.file.file_size;
-		frag_idx = inode->data.file.fragment_index;
-		frag_off = inode->data.file.fragment_offset;
-	} else {
-		return -1;
-	}
-
-	if (inode->num_file_blocks * data->block_size >= filesz) {
-		*out = NULL;
-		return 0;
-	}
-
-	frag_sz = filesz % data->block_size;
-
-	if (precache_fragment_block(data, frag_idx))
-		return -1;
-
-	if (frag_off + frag_sz > data->block_size)
-		return -1;
-
-	blk = alloc_flex(sizeof(*blk), 1, frag_sz);
-	if (blk == NULL)
-		return -1;
-
-	blk->size = frag_sz;
-	memcpy(blk->data, (char *)data->frag_block->data + frag_off, frag_sz);
-
-	*out = blk;
-	return 0;
-}
-
-ssize_t sqfs_data_reader_read(sqfs_data_reader_t *data,
-			      const sqfs_inode_generic_t *inode,
-			      uint64_t offset, void *buffer, size_t size)
-{
-	uint32_t frag_idx, frag_off;
-	size_t i, diff, total = 0;
-	uint64_t off, filesz;
-	char *ptr;
-
-	/* work out file location and size */
-	if (inode->base.type == SQFS_INODE_EXT_FILE) {
-		off = inode->data.file_ext.blocks_start;
-		filesz = inode->data.file_ext.file_size;
-		frag_idx = inode->data.file_ext.fragment_idx;
-		frag_off = inode->data.file_ext.fragment_offset;
-	} else {
-		off = inode->data.file.blocks_start;
-		filesz = inode->data.file.file_size;
-		frag_idx = inode->data.file.fragment_index;
-		frag_off = inode->data.file.fragment_offset;
-	}
-
-	/* find location of the first block */
-	i = 0;
-
-	while (offset > data->block_size && i < inode->num_file_blocks) {
-		off += SQFS_ON_DISK_BLOCK_SIZE(inode->block_sizes[i++]);
-		offset -= data->block_size;
-
-		if (filesz >= data->block_size) {
-			filesz -= data->block_size;
-		} else {
-			filesz = 0;
-		}
-	}
-
-	/* copy data from blocks */
-	while (i < inode->num_file_blocks && size > 0 && filesz > 0) {
-		diff = data->block_size - offset;
-		if (size < diff)
-			diff = size;
-
-		if (SQFS_IS_SPARSE_BLOCK(inode->block_sizes[i])) {
-			memset(buffer, 0, diff);
-		} else {
-			if (precache_data_block(data, off,
-						inode->block_sizes[i])) {
-				return -1;
-			}
-
-			memcpy(buffer, (char *)data->data_block->data + offset,
-			       diff);
-			off += SQFS_ON_DISK_BLOCK_SIZE(inode->block_sizes[i]);
-		}
-
-		if (filesz >= data->block_size) {
-			filesz -= data->block_size;
-		} else {
-			filesz = 0;
-		}
-
-		++i;
-		offset = 0;
-		size -= diff;
-		total += diff;
-		buffer = (char *)buffer + diff;
-	}
-
-	/* copy from fragment */
-	if (i == inode->num_file_blocks && size > 0 && filesz > 0) {
-		if (precache_fragment_block(data, frag_idx))
-			return -1;
-
-		if (frag_off + filesz > data->block_size)
-			goto fail_range;
-
-		if (offset >= filesz)
-			return total;
-
-		if (offset + size > filesz)
-			size = filesz - offset;
-
-		if (size == 0)
-			return total;
-
-		ptr = (char *)data->frag_block->data + frag_off + offset;
-		memcpy(buffer, ptr, size);
-		total += size;
-	}
-
-	return total;
-fail_range:
-	fputs("attempted to read past fragment block limits\n", stderr);
-	return -1;
-}
diff --git a/lib/sqfshelper/data_reader_dump.c b/lib/sqfshelper/data_reader_dump.c
index 0c7a0cc..e28bf20 100644
--- a/lib/sqfshelper/data_reader_dump.c
+++ b/lib/sqfshelper/data_reader_dump.c
@@ -7,7 +7,7 @@
 #include "config.h"
 
 #include "sqfs/block_processor.h"
-#include "data_reader.h"
+#include "sqfs/data_reader.h"
 #include "highlevel.h"
 #include "util.h"