Rename sqfs_data_writer_t back to sqfs_block_processor_t

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

7 files changed, 1223 insertions, 0 deletions

diff --git a/lib/sqfs/block_processor/block.c b/lib/sqfs/block_processor/block.c
new file mode 100644
index 0000000..49892be
--- /dev/null
+++ b/lib/sqfs/block_processor/block.c
@@ -0,0 +1,203 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * process_block.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "internal.h"
+
+#include <string.h>
+
+static int store_block_location(sqfs_block_processor_t *proc, sqfs_u64 offset,
+				sqfs_u32 size, sqfs_u32 chksum)
+{
+	size_t new_sz;
+	void *new;
+
+	if (proc->num_blocks == proc->max_blocks) {
+		new_sz = proc->max_blocks * 2;
+		new = realloc(proc->blocks, sizeof(proc->blocks[0]) * new_sz);
+
+		if (new == NULL)
+			return SQFS_ERROR_ALLOC;
+
+		proc->blocks = new;
+		proc->max_blocks = new_sz;
+	}
+
+	proc->blocks[proc->num_blocks].offset = offset;
+	proc->blocks[proc->num_blocks].hash = MK_BLK_HASH(chksum, size);
+	proc->num_blocks += 1;
+	return 0;
+}
+
+static size_t deduplicate_blocks(sqfs_block_processor_t *proc, size_t count)
+{
+	size_t i, j;
+
+	for (i = 0; i < proc->file_start; ++i) {
+		for (j = 0; j < count; ++j) {
+			if (proc->blocks[i + j].hash !=
+			    proc->blocks[proc->file_start + j].hash)
+				break;
+		}
+
+		if (j == count)
+			break;
+	}
+
+	return i;
+}
+
+static int align_file(sqfs_block_processor_t *proc, sqfs_block_t *blk)
+{
+	sqfs_u32 chksum;
+	void *padding;
+	sqfs_u64 size;
+	size_t diff;
+	int ret;
+
+	if (!(blk->flags & SQFS_BLK_ALIGN))
+		return 0;
+
+	size = proc->file->get_size(proc->file);
+	diff = size % proc->devblksz;
+	if (diff == 0)
+		return 0;
+
+	padding = calloc(1, diff);
+	if (padding == 0)
+		return SQFS_ERROR_ALLOC;
+
+	if (proc->hooks != NULL && proc->hooks->prepare_padding != NULL)
+		proc->hooks->prepare_padding(proc->user_ptr, padding, diff);
+
+	chksum = crc32(0, padding, diff);
+
+	ret = proc->file->write_at(proc->file, size, padding, diff);
+	free(padding);
+	if (ret)
+		return ret;
+
+	return store_block_location(proc, size, diff | (1 << 24), chksum);
+}
+
+int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
+{
+	sqfs_u64 offset, bytes;
+	size_t start, count;
+	sqfs_u32 out;
+	int err;
+
+	if (proc->hooks != NULL && proc->hooks->pre_block_write != NULL) {
+		proc->hooks->pre_block_write(proc->user_ptr, blk, proc->file);
+	}
+
+	if (blk->flags & SQFS_BLK_FIRST_BLOCK) {
+		proc->start = proc->file->get_size(proc->file);
+		proc->file_start = proc->num_blocks;
+
+		err = align_file(proc, blk);
+		if (err)
+			return err;
+	}
+
+	if (blk->size != 0) {
+		out = blk->size;
+		if (!(blk->flags & SQFS_BLK_IS_COMPRESSED))
+			out |= 1 << 24;
+
+		offset = proc->file->get_size(proc->file);
+
+		if (blk->flags & SQFS_BLK_FRAGMENT_BLOCK) {
+			err = sqfs_frag_table_set(proc->frag_tbl, blk->index,
+						  offset, out);
+			if (err)
+				return err;
+		} else {
+			blk->inode->extra[blk->index] = out;
+		}
+
+		err = store_block_location(proc, offset, out, blk->checksum);
+		if (err)
+			return err;
+
+		err = proc->file->write_at(proc->file, offset,
+					   blk->data, blk->size);
+		if (err)
+			return err;
+	}
+
+	if (proc->hooks != NULL && proc->hooks->post_block_write != NULL) {
+		proc->hooks->post_block_write(proc->user_ptr, blk, proc->file);
+	}
+
+	if (blk->flags & SQFS_BLK_LAST_BLOCK) {
+		err = align_file(proc, blk);
+		if (err)
+			return err;
+
+		count = proc->num_blocks - proc->file_start;
+		start = deduplicate_blocks(proc, count);
+		offset = proc->blocks[start].offset;
+
+		sqfs_inode_set_file_block_start(blk->inode, offset);
+
+		if (start >= proc->file_start)
+			return 0;
+
+		offset = start + count;
+		if (offset >= proc->file_start) {
+			count = proc->num_blocks - offset;
+			proc->num_blocks = offset;
+		} else {
+			proc->num_blocks = proc->file_start;
+		}
+
+		if (proc->hooks != NULL &&
+		    proc->hooks->notify_blocks_erased != NULL) {
+			bytes = proc->file->get_size(proc->file) - proc->start;
+
+			proc->hooks->notify_blocks_erased(proc->user_ptr,
+							  count, bytes);
+		}
+
+		err = proc->file->truncate(proc->file, proc->start);
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+int block_processor_do_block(sqfs_block_t *block, sqfs_compressor_t *cmp,
+			     sqfs_u8 *scratch, size_t scratch_size)
+{
+	ssize_t ret;
+
+	if (block->size == 0) {
+		block->checksum = 0;
+		return 0;
+	}
+
+	block->checksum = crc32(0, block->data, block->size);
+
+	if (block->flags & SQFS_BLK_IS_FRAGMENT)
+		return 0;
+
+	if (!(block->flags & SQFS_BLK_DONT_COMPRESS)) {
+		ret = cmp->do_block(cmp, block->data, block->size,
+				    scratch, scratch_size);
+		if (ret < 0)
+			return ret;
+
+		if (ret > 0) {
+			memcpy(block->data, scratch, ret);
+			block->size = ret;
+			block->flags |= SQFS_BLK_IS_COMPRESSED;
+		}
+	}
+
+	return 0;
+}
diff --git a/lib/sqfs/block_processor/common.c b/lib/sqfs/block_processor/common.c
new file mode 100644
index 0000000..c6375dd
--- /dev/null
+++ b/lib/sqfs/block_processor/common.c
@@ -0,0 +1,72 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * common.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "internal.h"
+
+void free_blk_list(sqfs_block_t *list)
+{
+	sqfs_block_t *it;
+
+	while (list != NULL) {
+		it = list;
+		list = list->next;
+		free(it);
+	}
+}
+
+int block_processor_init(sqfs_block_processor_t *proc, size_t max_block_size,
+			 sqfs_compressor_t *cmp, unsigned int num_workers,
+			 size_t max_backlog, size_t devblksz, sqfs_file_t *file)
+{
+	proc->max_block_size = max_block_size;
+	proc->num_workers = num_workers;
+	proc->max_backlog = max_backlog;
+	proc->devblksz = devblksz;
+	proc->cmp = cmp;
+	proc->file = file;
+	proc->max_blocks = INIT_BLOCK_COUNT;
+
+	proc->frag_tbl = sqfs_frag_table_create(0);
+	if (proc->frag_tbl == NULL)
+		return -1;
+
+	proc->blocks = alloc_array(sizeof(proc->blocks[0]), proc->max_blocks);
+	if (proc->blocks == NULL)
+		return -1;
+
+	return 0;
+}
+
+void block_processor_cleanup(sqfs_block_processor_t *proc)
+{
+	if (proc->frag_tbl != NULL)
+		sqfs_frag_table_destroy(proc->frag_tbl);
+	free_blk_list(proc->queue);
+	free_blk_list(proc->done);
+	free(proc->blk_current);
+	free(proc->frag_block);
+	free(proc->blocks);
+	free(proc);
+}
+
+int sqfs_block_processor_write_fragment_table(sqfs_block_processor_t *proc,
+					      sqfs_super_t *super)
+{
+	return sqfs_frag_table_write(proc->frag_tbl, proc->file,
+				     super, proc->cmp);
+}
+
+int sqfs_block_processor_set_hooks(sqfs_block_processor_t *proc, void *user_ptr,
+				   const sqfs_block_hooks_t *hooks)
+{
+	if (hooks->size != sizeof(*hooks))
+		return SQFS_ERROR_UNSUPPORTED;
+
+	proc->hooks = hooks;
+	proc->user_ptr = user_ptr;
+	return 0;
+}
diff --git a/lib/sqfs/block_processor/fileapi.c b/lib/sqfs/block_processor/fileapi.c
new file mode 100644
index 0000000..9e59c1d
--- /dev/null
+++ b/lib/sqfs/block_processor/fileapi.c
@@ -0,0 +1,188 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * fileapi.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "internal.h"
+
+static bool is_zero_block(unsigned char *ptr, size_t size)
+{
+	return ptr[0] == 0 && memcmp(ptr, ptr + 1, size - 1) == 0;
+}
+
+static int enqueue_block(sqfs_block_processor_t *proc, sqfs_block_t *block)
+{
+	int status;
+
+	while (proc->backlog > proc->max_backlog) {
+		status = wait_completed(proc);
+		if (status)
+			return status;
+	}
+
+	if (proc->backlog == proc->max_backlog)
+		proc->notify_threads = true;
+
+	return append_to_work_queue(proc, block, proc->notify_threads);
+}
+
+static int add_sentinel_block(sqfs_block_processor_t *proc)
+{
+	sqfs_block_t *blk = calloc(1, sizeof(*blk));
+
+	if (blk == NULL)
+		return test_and_set_status(proc, SQFS_ERROR_ALLOC);
+
+	blk->inode = proc->inode;
+	blk->flags = proc->blk_flags | SQFS_BLK_LAST_BLOCK;
+
+	return enqueue_block(proc, blk);
+}
+
+int sqfs_block_processor_begin_file(sqfs_block_processor_t *proc,
+				    sqfs_inode_generic_t *inode, sqfs_u32 flags)
+{
+	if (proc->inode != NULL)
+		return test_and_set_status(proc, SQFS_ERROR_INTERNAL);
+
+	if (flags & ~SQFS_BLK_USER_SETTABLE_FLAGS)
+		return test_and_set_status(proc, SQFS_ERROR_UNSUPPORTED);
+
+	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);
+		return 0;
+	}
+
+	if (block->size < proc->max_block_size &&
+	    !(block->flags & SQFS_BLK_DONT_FRAGMENT)) {
+		block->flags |= SQFS_BLK_IS_FRAGMENT;
+	} else {
+		proc->inode->num_file_blocks += 1;
+		proc->blk_flags &= ~SQFS_BLK_FIRST_BLOCK;
+	}
+
+	return enqueue_block(proc, block);
+}
+
+int sqfs_block_processor_append(sqfs_block_processor_t *proc, const void *data,
+				size_t size)
+{
+	size_t diff;
+	void *new;
+	int err;
+
+	while (size > 0) {
+		if (proc->blk_current == NULL) {
+			new = alloc_flex(sizeof(*proc->blk_current), 1,
+					 proc->max_block_size);
+
+			if (new == NULL)
+				return test_and_set_status(proc,
+							   SQFS_ERROR_ALLOC);
+
+			proc->blk_current = new;
+		}
+
+		diff = proc->max_block_size - proc->blk_current->size;
+
+		if (diff == 0) {
+			err = flush_block(proc, proc->blk_current);
+			proc->blk_current = NULL;
+			if (err)
+				return err;
+			continue;
+		}
+
+		if (diff > size)
+			diff = size;
+
+		memcpy(proc->blk_current->data + proc->blk_current->size,
+		       data, diff);
+
+		size -= diff;
+		proc->blk_current->size += diff;
+		data = (const char *)data + diff;
+	}
+
+	if (proc->blk_current != NULL &&
+	    proc->blk_current->size == proc->max_block_size) {
+		err = flush_block(proc, proc->blk_current);
+		proc->blk_current = NULL;
+		return err;
+	}
+
+	return 0;
+}
+
+int sqfs_block_processor_end_file(sqfs_block_processor_t *proc)
+{
+	int err;
+
+	if (proc->inode == NULL)
+		return test_and_set_status(proc, SQFS_ERROR_INTERNAL);
+
+	if (!(proc->blk_flags & SQFS_BLK_FIRST_BLOCK)) {
+		if (proc->blk_current != NULL &&
+		    (proc->blk_flags & SQFS_BLK_DONT_FRAGMENT)) {
+			proc->blk_flags |= SQFS_BLK_LAST_BLOCK;
+		} else {
+			err = add_sentinel_block(proc);
+			if (err)
+				return err;
+		}
+	}
+
+	if (proc->blk_current != NULL) {
+		err = flush_block(proc, proc->blk_current);
+		proc->blk_current = NULL;
+	}
+
+	proc->inode = NULL;
+	proc->blk_flags = 0;
+	proc->blk_index = 0;
+	return 0;
+}
+
+int sqfs_block_processor_finish(sqfs_block_processor_t *proc)
+{
+	int status = 0;
+
+	append_to_work_queue(proc, NULL, true);
+
+	while (proc->backlog > 0) {
+		status = wait_completed(proc);
+		if (status)
+			return status;
+	}
+
+	if (proc->frag_block != NULL) {
+		status = append_to_work_queue(proc, proc->frag_block, true);
+		proc->frag_block = NULL;
+
+		if (status)
+			return status;
+
+		status = wait_completed(proc);
+	}
+
+	return status;
+}
diff --git a/lib/sqfs/block_processor/fragment.c b/lib/sqfs/block_processor/fragment.c
new file mode 100644
index 0000000..3701b3c
--- /dev/null
+++ b/lib/sqfs/block_processor/fragment.c
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * fragtbl.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "internal.h"
+
+int process_completed_fragment(sqfs_block_processor_t *proc, sqfs_block_t *frag,
+			       sqfs_block_t **blk_out)
+{
+	sqfs_u32 index, offset;
+	size_t size;
+	int err;
+
+	err = sqfs_frag_table_find_tail_end(proc->frag_tbl,
+					    frag->checksum, frag->size,
+					    &index, &offset);
+	if (err == 0)
+		goto out_duplicate;
+
+	if (proc->frag_block != NULL) {
+		size = proc->frag_block->size + frag->size;
+
+		if (size > proc->max_block_size) {
+			*blk_out = proc->frag_block;
+			proc->frag_block = NULL;
+		}
+	}
+
+	if (proc->frag_block == NULL) {
+		size = sizeof(sqfs_block_t) + proc->max_block_size;
+
+		err= sqfs_frag_table_append(proc->frag_tbl, 0, 0, &index);
+		if (err)
+			goto fail;
+
+		proc->frag_block = calloc(1, size);
+		if (proc->frag_block == NULL) {
+			err = SQFS_ERROR_ALLOC;
+			goto fail;
+		}
+
+		proc->frag_block->index = index;
+		proc->frag_block->flags = SQFS_BLK_FRAGMENT_BLOCK;
+	}
+
+	err = sqfs_frag_table_add_tail_end(proc->frag_tbl,
+					   proc->frag_block->index,
+					   proc->frag_block->size,
+					   frag->size, frag->checksum);
+	if (err)
+		goto fail;
+
+	sqfs_inode_set_frag_location(frag->inode, proc->frag_block->index,
+				     proc->frag_block->size);
+
+	if (proc->hooks != NULL && proc->hooks->pre_fragment_store != NULL) {
+		proc->hooks->pre_fragment_store(proc->user_ptr, frag);
+	}
+
+	memcpy(proc->frag_block->data + proc->frag_block->size,
+	       frag->data, frag->size);
+
+	proc->frag_block->flags |= (frag->flags & SQFS_BLK_DONT_COMPRESS);
+	proc->frag_block->size += frag->size;
+	return 0;
+fail:
+	free(*blk_out);
+	*blk_out = NULL;
+	return err;
+out_duplicate:
+	sqfs_inode_set_frag_location(frag->inode, index, offset);
+
+	if (proc->hooks != NULL &&
+	    proc->hooks->notify_fragment_discard != NULL) {
+		proc->hooks->notify_fragment_discard(proc->user_ptr, frag);
+	}
+	return 0;
+}
diff --git a/lib/sqfs/block_processor/internal.h b/lib/sqfs/block_processor/internal.h
new file mode 100644
index 0000000..40871b9
--- /dev/null
+++ b/lib/sqfs/block_processor/internal.h
@@ -0,0 +1,141 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * internal.h
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef INTERNAL_H
+#define INTERNAL_H
+
+#include "config.h"
+
+#include "sqfs/block_processor.h"
+#include "sqfs/frag_table.h"
+#include "sqfs/compressor.h"
+#include "sqfs/inode.h"
+#include "sqfs/table.h"
+#include "sqfs/error.h"
+#include "sqfs/block.h"
+#include "sqfs/io.h"
+#include "../util.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include <zlib.h>
+
+#ifdef WITH_PTHREAD
+#include <pthread.h>
+#include <signal.h>
+#elif defined(_WIN32) || defined(__WINDOWS__)
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#endif
+
+
+#define MK_BLK_HASH(chksum, size) \
+	(((sqfs_u64)(size) << 32) | (sqfs_u64)(chksum))
+
+#define INIT_BLOCK_COUNT (128)
+
+
+typedef struct {
+	sqfs_u64 offset;
+	sqfs_u64 hash;
+} blk_info_t;
+
+
+typedef struct compress_worker_t compress_worker_t;
+
+struct sqfs_block_processor_t {
+	/* synchronization primitives */
+#ifdef WITH_PTHREAD
+	pthread_mutex_t mtx;
+	pthread_cond_t queue_cond;
+	pthread_cond_t done_cond;
+#elif defined(_WIN32) || defined(__WINDOWS__)
+	CRITICAL_SECTION mtx;
+	CONDITION_VARIABLE queue_cond;
+	CONDITION_VARIABLE done_cond;
+#endif
+
+	/* needs rw access by worker and main thread */
+	sqfs_block_t *queue;
+	sqfs_block_t *queue_last;
+
+	sqfs_block_t *done;
+	size_t backlog;
+	int status;
+
+	/* used by main thread only */
+	sqfs_u32 enqueue_id;
+	sqfs_u32 dequeue_id;
+
+	unsigned int num_workers;
+	size_t max_backlog;
+
+	size_t devblksz;
+	sqfs_file_t *file;
+
+	sqfs_frag_table_t *frag_tbl;
+
+	sqfs_u64 start;
+
+	size_t file_start;
+	size_t num_blocks;
+	size_t max_blocks;
+	blk_info_t *blocks;
+	sqfs_compressor_t *cmp;
+
+	sqfs_block_t *frag_block;
+
+	const sqfs_block_hooks_t *hooks;
+	void *user_ptr;
+	bool notify_threads;
+
+	/* file API */
+	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;
+
+#if defined(WITH_PTHREAD) || defined(_WIN32) || defined(__WINDOWS__)
+	compress_worker_t *workers[];
+#else
+	sqfs_u8 scratch[];
+#endif
+};
+
+SQFS_INTERNAL int process_completed_block(sqfs_block_processor_t *proc,
+					  sqfs_block_t *block);
+
+SQFS_INTERNAL
+int process_completed_fragment(sqfs_block_processor_t *proc, sqfs_block_t *frag,
+			       sqfs_block_t **blk_out);
+
+SQFS_INTERNAL void free_blk_list(sqfs_block_t *list);
+
+SQFS_INTERNAL
+int block_processor_init(sqfs_block_processor_t *proc, size_t max_block_size,
+			 sqfs_compressor_t *cmp, unsigned int num_workers,
+			 size_t max_backlog, size_t devblksz,
+			 sqfs_file_t *file);
+
+SQFS_INTERNAL void block_processor_cleanup(sqfs_block_processor_t *proc);
+
+SQFS_INTERNAL
+int block_processor_do_block(sqfs_block_t *block, sqfs_compressor_t *cmp,
+			     sqfs_u8 *scratch, size_t scratch_size);
+
+SQFS_INTERNAL
+int test_and_set_status(sqfs_block_processor_t *proc, int status);
+
+SQFS_INTERNAL
+int append_to_work_queue(sqfs_block_processor_t *proc, sqfs_block_t *block,
+			 bool notify_threads);
+
+SQFS_INTERNAL int wait_completed(sqfs_block_processor_t *proc);
+
+#endif /* INTERNAL_H */
diff --git a/lib/sqfs/block_processor/serial.c b/lib/sqfs/block_processor/serial.c
new file mode 100644
index 0000000..eedb19c
--- /dev/null
+++ b/lib/sqfs/block_processor/serial.c
@@ -0,0 +1,88 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * serial.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "internal.h"
+
+sqfs_block_processor_t *sqfs_block_processor_create(size_t max_block_size,
+						    sqfs_compressor_t *cmp,
+						    unsigned int num_workers,
+						    size_t max_backlog,
+						    size_t devblksz,
+						    sqfs_file_t *file)
+{
+	sqfs_block_processor_t *proc;
+
+	proc = alloc_flex(sizeof(*proc), 1, max_block_size);
+
+	if (proc == NULL)
+		return NULL;
+
+	if (block_processor_init(proc, max_block_size, cmp, num_workers,
+				 max_backlog, devblksz, file)) {
+		block_processor_cleanup(proc);
+		return NULL;
+	}
+
+	return proc;
+}
+
+void sqfs_block_processor_destroy(sqfs_block_processor_t *proc)
+{
+	block_processor_cleanup(proc);
+}
+
+int test_and_set_status(sqfs_block_processor_t *proc, int status)
+{
+	if (proc->status == 0)
+		proc->status = status;
+
+	return proc->status;
+}
+
+int append_to_work_queue(sqfs_block_processor_t *proc, sqfs_block_t *block,
+			 bool signal_threads)
+{
+	sqfs_block_t *fragblk = NULL;
+	(void)signal_threads;
+
+	if (proc->status != 0 || block == NULL) {
+		free(block);
+		return proc->status;
+	}
+
+	if (block->flags & SQFS_BLK_IS_FRAGMENT) {
+		block->checksum = crc32(0, block->data, block->size);
+
+		proc->status = process_completed_fragment(proc, block,
+							  &fragblk);
+		free(block);
+
+		if (proc->status != 0) {
+			free(fragblk);
+			return proc->status;
+		}
+
+		if (fragblk == NULL)
+			return 0;
+
+		block = fragblk;
+	}
+
+	proc->status = block_processor_do_block(block, proc->cmp, proc->scratch,
+						proc->max_block_size);
+
+	if (proc->status == 0)
+		proc->status = process_completed_block(proc, block);
+
+	free(block);
+	return proc->status;
+}
+
+int wait_completed(sqfs_block_processor_t *proc)
+{
+	return proc->status;
+}
diff --git a/lib/sqfs/block_processor/winpthread.c b/lib/sqfs/block_processor/winpthread.c
new file mode 100644
index 0000000..b16a17c
--- /dev/null
+++ b/lib/sqfs/block_processor/winpthread.c
@@ -0,0 +1,450 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * winpthread.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "internal.h"
+
+#if defined(_WIN32) || defined(__WINDOWS__)
+#	define LOCK(mtx) EnterCriticalSection(mtx)
+#	define UNLOCK(mtx) LeaveCriticalSection(mtx)
+#	define AWAIT(cond, mtx) SleepConditionVariableCS(cond, mtx, INFINITE)
+#	define SIGNAL_ALL(cond) WakeAllConditionVariable(cond)
+#	define THREAD_EXIT_SUCCESS 0
+#	define THREAD_TYPE DWORD WINAPI
+#	define THREAD_ARG LPVOID
+#	define THREAD_HANDLE HANDLE
+#else
+#	define LOCK(mtx) pthread_mutex_lock(mtx)
+#	define UNLOCK(mtx) pthread_mutex_unlock(mtx)
+#	define AWAIT(cond, mtx) pthread_cond_wait(cond, mtx)
+#	define SIGNAL_ALL(cond) pthread_cond_broadcast(cond)
+#	define THREAD_EXIT_SUCCESS NULL
+#	define THREAD_TYPE void *
+#	define THREAD_ARG void *
+#	define THREAD_HANDLE pthread_t
+#endif
+
+struct compress_worker_t {
+	sqfs_block_processor_t *shared;
+	sqfs_compressor_t *cmp;
+	THREAD_HANDLE thread;
+	sqfs_u8 scratch[];
+};
+
+static THREAD_TYPE worker_proc(THREAD_ARG arg)
+{
+	compress_worker_t *worker = arg;
+	sqfs_block_processor_t *shared = worker->shared;
+	sqfs_block_t *it, *prev, *blk = NULL;
+	int status = 0;
+
+	for (;;) {
+		LOCK(&shared->mtx);
+		if (blk != NULL) {
+			it = shared->done;
+			prev = NULL;
+
+			while (it != NULL) {
+				if (it->sequence_number >= blk->sequence_number)
+					break;
+				prev = it;
+				it = it->next;
+			}
+
+			if (prev == NULL) {
+				blk->next = shared->done;
+				shared->done = blk;
+			} else {
+				blk->next = prev->next;
+				prev->next = blk;
+			}
+
+			if (status != 0 && shared->status == 0)
+				shared->status = status;
+			SIGNAL_ALL(&shared->done_cond);
+		}
+
+		while (shared->queue == NULL && shared->status == 0)
+			AWAIT(&shared->queue_cond, &shared->mtx);
+
+		if (shared->status == 0) {
+			blk = shared->queue;
+			shared->queue = blk->next;
+			blk->next = NULL;
+
+			if (shared->queue == NULL)
+				shared->queue_last = NULL;
+		} else {
+			blk = NULL;
+		}
+		UNLOCK(&shared->mtx);
+
+		if (blk == NULL)
+			break;
+
+		status = block_processor_do_block(blk, worker->cmp,
+						  worker->scratch,
+						  shared->max_block_size);
+	}
+
+	return THREAD_EXIT_SUCCESS;
+}
+
+#if defined(_WIN32) || defined(__WINDOWS__)
+sqfs_block_processor_t *sqfs_block_processor_create(size_t max_block_size,
+						    sqfs_compressor_t *cmp,
+						    unsigned int num_workers,
+						    size_t max_backlog,
+						    size_t devblksz,
+						    sqfs_file_t *file)
+{
+	sqfs_block_processor_t *proc;
+	unsigned int i;
+
+	if (num_workers < 1)
+		num_workers = 1;
+
+	proc = alloc_flex(sizeof(*proc),
+			  sizeof(proc->workers[0]), num_workers);
+	if (proc == NULL)
+		return NULL;
+
+	InitializeCriticalSection(&proc->mtx);
+	InitializeConditionVariable(&proc->queue_cond);
+	InitializeConditionVariable(&proc->done_cond);
+
+	if (block_processor_init(proc, max_block_size, cmp, num_workers,
+				 max_backlog, devblksz, file)) {
+		goto fail;
+	}
+
+	for (i = 0; i < num_workers; ++i) {
+		proc->workers[i] = alloc_flex(sizeof(compress_worker_t),
+					      1, max_block_size);
+
+		if (proc->workers[i] == NULL)
+			goto fail;
+
+		proc->workers[i]->shared = proc;
+		proc->workers[i]->cmp = cmp->create_copy(cmp);
+
+		if (proc->workers[i]->cmp == NULL)
+			goto fail;
+
+		proc->workers[i]->thread = CreateThread(NULL, 0, worker_proc,
+							proc->workers[i], 0, 0);
+		if (proc->workers[i]->thread == NULL)
+			goto fail;
+	}
+
+	return proc;
+fail:
+	sqfs_block_processor_destroy(proc);
+	return NULL;
+}
+
+void sqfs_block_processor_destroy(sqfs_block_processor_t *proc)
+{
+	unsigned int i;
+
+	EnterCriticalSection(&proc->mtx);
+	proc->status = -1;
+	WakeAllConditionVariable(&proc->queue_cond);
+	LeaveCriticalSection(&proc->mtx);
+
+	for (i = 0; i < proc->num_workers; ++i) {
+		if (proc->workers[i] == NULL)
+			continue;
+
+		if (proc->workers[i]->thread != NULL) {
+			WaitForSingleObject(proc->workers[i]->thread, INFINITE);
+			CloseHandle(proc->workers[i]->thread);
+		}
+
+		if (proc->workers[i]->cmp != NULL)
+			proc->workers[i]->cmp->destroy(proc->workers[i]->cmp);
+
+		free(proc->workers[i]);
+	}
+
+	DeleteCriticalSection(&proc->mtx);
+	block_processor_cleanup(proc);
+}
+#else
+sqfs_block_processor_t *sqfs_block_processor_create(size_t max_block_size,
+						    sqfs_compressor_t *cmp,
+						    unsigned int num_workers,
+						    size_t max_backlog,
+						    size_t devblksz,
+						    sqfs_file_t *file)
+{
+	sqfs_block_processor_t *proc;
+	sigset_t set, oldset;
+	unsigned int i;
+	int ret;
+
+	if (num_workers < 1)
+		num_workers = 1;
+
+	proc = alloc_flex(sizeof(*proc),
+			  sizeof(proc->workers[0]), num_workers);
+	if (proc == NULL)
+		return NULL;
+
+	proc->mtx = (pthread_mutex_t)PTHREAD_MUTEX_INITIALIZER;
+	proc->queue_cond = (pthread_cond_t)PTHREAD_COND_INITIALIZER;
+	proc->done_cond = (pthread_cond_t)PTHREAD_COND_INITIALIZER;
+
+	if (block_processor_init(proc, max_block_size, cmp, num_workers,
+				 max_backlog, devblksz, file)) {
+		goto fail_init;
+	}
+
+	for (i = 0; i < num_workers; ++i) {
+		proc->workers[i] = alloc_flex(sizeof(compress_worker_t),
+					      1, max_block_size);
+
+		if (proc->workers[i] == NULL)
+			goto fail_init;
+
+		proc->workers[i]->shared = proc;
+		proc->workers[i]->cmp = cmp->create_copy(cmp);
+
+		if (proc->workers[i]->cmp == NULL)
+			goto fail_init;
+	}
+
+	sigfillset(&set);
+	pthread_sigmask(SIG_SETMASK, &set, &oldset);
+
+	for (i = 0; i < num_workers; ++i) {
+		ret = pthread_create(&proc->workers[i]->thread, NULL,
+				     worker_proc, proc->workers[i]);
+
+		if (ret != 0)
+			goto fail_thread;
+	}
+
+	pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+
+	return proc;
+fail_thread:
+	pthread_mutex_lock(&proc->mtx);
+	proc->status = -1;
+	pthread_cond_broadcast(&proc->queue_cond);
+	pthread_mutex_unlock(&proc->mtx);
+
+	for (i = 0; i < num_workers; ++i) {
+		if (proc->workers[i]->thread > 0) {
+			pthread_join(proc->workers[i]->thread, NULL);
+		}
+	}
+	pthread_sigmask(SIG_SETMASK, &oldset, NULL);
+fail_init:
+	for (i = 0; i < num_workers; ++i) {
+		if (proc->workers[i] != NULL) {
+			if (proc->workers[i]->cmp != NULL) {
+				proc->workers[i]->cmp->
+					destroy(proc->workers[i]->cmp);
+			}
+
+			free(proc->workers[i]);
+		}
+	}
+	pthread_cond_destroy(&proc->done_cond);
+	pthread_cond_destroy(&proc->queue_cond);
+	pthread_mutex_destroy(&proc->mtx);
+	block_processor_cleanup(proc);
+	return NULL;
+}
+
+void sqfs_block_processor_destroy(sqfs_block_processor_t *proc)
+{
+	unsigned int i;
+
+	pthread_mutex_lock(&proc->mtx);
+	proc->status = -1;
+	pthread_cond_broadcast(&proc->queue_cond);
+	pthread_mutex_unlock(&proc->mtx);
+
+	for (i = 0; i < proc->num_workers; ++i) {
+		pthread_join(proc->workers[i]->thread, NULL);
+
+		proc->workers[i]->cmp->destroy(proc->workers[i]->cmp);
+		free(proc->workers[i]);
+	}
+
+	pthread_cond_destroy(&proc->done_cond);
+	pthread_cond_destroy(&proc->queue_cond);
+	pthread_mutex_destroy(&proc->mtx);
+
+	block_processor_cleanup(proc);
+}
+#endif
+
+int append_to_work_queue(sqfs_block_processor_t *proc, sqfs_block_t *block,
+			 bool signal_threads)
+{
+	int status;
+
+	LOCK(&proc->mtx);
+	status = proc->status;
+	if (status != 0)
+		goto out;
+
+	if (block != NULL) {
+		if (proc->queue_last == NULL) {
+			proc->queue = proc->queue_last = block;
+		} else {
+			proc->queue_last->next = block;
+			proc->queue_last = block;
+		}
+
+		block->sequence_number = proc->enqueue_id++;
+		block->next = NULL;
+		proc->backlog += 1;
+		block = NULL;
+	}
+out:
+	if (signal_threads)
+		SIGNAL_ALL(&proc->queue_cond);
+
+	UNLOCK(&proc->mtx);
+	free(block);
+	return 0;
+}
+
+static sqfs_block_t *try_dequeue(sqfs_block_processor_t *proc)
+{
+	sqfs_block_t *queue, *it, *prev;
+
+	it = proc->done;
+	prev = NULL;
+
+	while (it != NULL && it->sequence_number == proc->dequeue_id) {
+		prev = it;
+		it = it->next;
+		proc->dequeue_id += 1;
+	}
+
+	if (prev == NULL) {
+		queue = NULL;
+	} else {
+		queue = proc->done;
+		prev->next = NULL;
+		proc->done = it;
+	}
+
+	return queue;
+}
+
+static sqfs_block_t *queue_merge(sqfs_block_t *lhs, sqfs_block_t *rhs)
+{
+	sqfs_block_t *it, *head = NULL, **next_ptr = &head;
+
+	while (lhs != NULL && rhs != NULL) {
+		if (lhs->sequence_number <= rhs->sequence_number) {
+			it = lhs;
+			lhs = lhs->next;
+		} else {
+			it = rhs;
+			rhs = rhs->next;
+		}
+
+		*next_ptr = it;
+		next_ptr = &it->next;
+	}
+
+	it = (lhs != NULL ? lhs : rhs);
+	*next_ptr = it;
+	return head;
+}
+
+static int process_done_queue(sqfs_block_processor_t *proc, sqfs_block_t *queue)
+{
+	sqfs_block_t *it, *block = NULL;
+	int status = 0;
+
+	while (queue != NULL && status == 0) {
+		it = queue;
+		queue = it->next;
+		proc->backlog -= 1;
+
+		if (it->flags & SQFS_BLK_IS_FRAGMENT) {
+			block = NULL;
+			status = process_completed_fragment(proc, it, &block);
+
+			if (block != NULL && status == 0) {
+				LOCK(&proc->mtx);
+				proc->dequeue_id = it->sequence_number;
+				block->sequence_number = it->sequence_number;
+
+				if (proc->queue == NULL) {
+					proc->queue = block;
+					proc->queue_last = block;
+				} else {
+					block->next = proc->queue;
+					proc->queue = block;
+				}
+
+				proc->backlog += 1;
+				proc->done = queue_merge(queue, proc->done);
+				SIGNAL_ALL(&proc->queue_cond);
+				UNLOCK(&proc->mtx);
+
+				queue = NULL;
+			} else {
+				free(block);
+			}
+		} else {
+			status = process_completed_block(proc, it);
+		}
+
+		free(it);
+	}
+
+	free_blk_list(queue);
+	return status;
+}
+
+int test_and_set_status(sqfs_block_processor_t *proc, int status)
+{
+	LOCK(&proc->mtx);
+	if (proc->status == 0) {
+		proc->status = status;
+	} else {
+		status = proc->status;
+	}
+	SIGNAL_ALL(&proc->queue_cond);
+	UNLOCK(&proc->mtx);
+	return status;
+}
+
+int wait_completed(sqfs_block_processor_t *proc)
+{
+	sqfs_block_t *queue;
+	int status;
+
+	LOCK(&proc->mtx);
+	for (;;) {
+		queue = try_dequeue(proc);
+		status = proc->status;
+
+		if (queue != NULL || status != 0)
+			break;
+
+		AWAIT(&proc->done_cond, &proc->mtx);
+	}
+	UNLOCK(&proc->mtx);
+
+	if (status != 0) {
+		free_blk_list(queue);
+		return status;
+	}
+
+	status = process_done_queue(proc, queue);
+	return status ? test_and_set_status(proc, status) : status;
+}