4 files changed, 1051 insertions, 0 deletions

diff --git a/lib/sqfs/src/block_processor/backend.c b/lib/sqfs/src/block_processor/backend.c
new file mode 100644
index 0000000..b443c9d
--- /dev/null
+++ b/lib/sqfs/src/block_processor/backend.c
@@ -0,0 +1,335 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * backend.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "internal.h"
+
+static int set_block_size(sqfs_inode_generic_t **inode,
+			  sqfs_u32 index, sqfs_u32 size)
+{
+	size_t min_size = (index + 1) * sizeof(sqfs_u32);
+	size_t avail = (*inode)->payload_bytes_available;
+	sqfs_inode_generic_t *new;
+	size_t newsz;
+
+	if (avail < min_size) {
+		newsz = avail ? avail : (sizeof(sqfs_u32) * 4);
+		while (newsz < min_size)
+			newsz *= 2;
+
+		if (SZ_ADD_OV(newsz, sizeof(**inode), &newsz))
+			return SQFS_ERROR_OVERFLOW;
+
+		if (sizeof(size_t) > sizeof(sqfs_u32)) {
+			if ((newsz - sizeof(**inode)) > 0x0FFFFFFFFUL)
+				return SQFS_ERROR_OVERFLOW;
+		}
+
+		new = realloc((*inode), newsz);
+		if (new == NULL)
+			return SQFS_ERROR_ALLOC;
+
+		(*inode) = new;
+		(*inode)->payload_bytes_available = newsz - sizeof(**inode);
+	}
+
+	(*inode)->extra[index] = size;
+
+	if (min_size >= (*inode)->payload_bytes_used)
+		(*inode)->payload_bytes_used = min_size;
+
+	return 0;
+}
+
+static void release_old_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
+{
+	blk->next = proc->free_list;
+	proc->free_list = blk;
+
+	proc->backlog -= 1;
+}
+
+static int process_completed_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
+{
+	sqfs_u64 location;
+	sqfs_u32 size;
+	int err;
+
+	if (blk->flags & SQFS_BLK_FRAGMENT_BLOCK) {
+		sqfs_block_t *it = proc->fblk_in_flight, *prev = NULL;
+
+		while (it != NULL && it->index != blk->index) {
+			prev = it;
+			it = it->next;
+		}
+
+		if (it != NULL) {
+			if (prev == NULL) {
+				proc->fblk_in_flight = it->next;
+			} else {
+				prev->next = it->next;
+			}
+			free(it);
+		}
+	}
+
+	err = proc->wr->write_data_block(proc->wr, blk->user, blk->size,
+					 blk->checksum,
+					 blk->flags & ~BLK_FLAG_INTERNAL,
+					 blk->data, &location);
+	if (err)
+		goto out;
+
+	proc->stats.output_bytes_generated += blk->size;
+
+	if (blk->flags & SQFS_BLK_IS_SPARSE) {
+		if (blk->inode != NULL) {
+			sqfs_inode_make_extended(*(blk->inode));
+			(*(blk->inode))->data.file_ext.sparse += blk->size;
+
+			err = set_block_size(blk->inode, blk->index, 0);
+			if (err)
+				goto out;
+		}
+		proc->stats.sparse_block_count += 1;
+	} else if (blk->size != 0) {
+		size = blk->size;
+		if (!(blk->flags & SQFS_BLK_IS_COMPRESSED))
+			size |= 1 << 24;
+
+		if (blk->flags & SQFS_BLK_FRAGMENT_BLOCK) {
+			if (proc->frag_tbl != NULL) {
+				err = sqfs_frag_table_set(proc->frag_tbl,
+							  blk->index, location,
+							  size);
+				if (err)
+					goto out;
+			}
+			proc->stats.frag_block_count += 1;
+		} else {
+			if (blk->inode != NULL) {
+				err = set_block_size(blk->inode, blk->index,
+						     size);
+				if (err)
+					goto out;
+			}
+			proc->stats.data_block_count += 1;
+		}
+	}
+
+	if (blk->flags & SQFS_BLK_LAST_BLOCK && blk->inode != NULL)
+		sqfs_inode_set_file_block_start(*(blk->inode), location);
+out:
+	release_old_block(proc, blk);
+	return err;
+}
+
+static int process_completed_fragment(sqfs_block_processor_t *proc,
+				      sqfs_block_t *frag)
+{
+	chunk_info_t *chunk = NULL, search;
+	struct hash_entry *entry;
+	sqfs_u32 index, offset;
+	int err;
+
+	if (frag->flags & SQFS_BLK_IS_SPARSE) {
+		if (frag->inode != NULL) {
+			sqfs_inode_make_extended(*(frag->inode));
+			set_block_size(frag->inode, frag->index, 0);
+			(*(frag->inode))->data.file_ext.sparse += frag->size;
+		}
+		proc->stats.sparse_block_count += 1;
+		release_old_block(proc, frag);
+		return 0;
+	}
+
+	proc->stats.total_frag_count += 1;
+
+	if (!(frag->flags & SQFS_BLK_DONT_DEDUPLICATE)) {
+		search.hash = frag->checksum;
+		search.size = frag->size;
+
+		proc->current_frag = frag;
+		proc->fblk_lookup_error = 0;
+		entry = hash_table_search_pre_hashed(proc->frag_ht,
+						     search.hash, &search);
+		proc->current_frag = NULL;
+
+		if (proc->fblk_lookup_error != 0) {
+			err = proc->fblk_lookup_error;
+			goto fail;
+		}
+
+		if (entry != NULL) {
+			if (frag->inode != NULL) {
+				chunk = entry->data;
+				sqfs_inode_set_frag_location(*(frag->inode),
+							     chunk->index,
+							     chunk->offset);
+			}
+			release_old_block(proc, frag);
+			return 0;
+		}
+	}
+
+	if (proc->frag_block != NULL) {
+		size_t size = proc->frag_block->size + frag->size;
+
+		if (size > proc->max_block_size) {
+			proc->frag_block->io_seq_num = proc->io_seq_num++;
+
+			err = enqueue_block(proc, proc->frag_block);
+			proc->frag_block = NULL;
+
+			if (err)
+				goto fail;
+		}
+	}
+
+	if (proc->frag_block == NULL) {
+		if (proc->frag_tbl == NULL) {
+			index = 0;
+		} else {
+			err = sqfs_frag_table_append(proc->frag_tbl,
+						     0, 0, &index);
+			if (err)
+				goto fail;
+		}
+
+		offset = 0;
+		proc->frag_block = frag;
+		proc->frag_block->index = index;
+		proc->frag_block->flags &=
+			(SQFS_BLK_DONT_COMPRESS | SQFS_BLK_ALIGN);
+		proc->frag_block->flags |= SQFS_BLK_FRAGMENT_BLOCK;
+	} else {
+		index = proc->frag_block->index;
+		offset = proc->frag_block->size;
+
+		memcpy(proc->frag_block->data + proc->frag_block->size,
+		       frag->data, frag->size);
+
+		proc->frag_block->size += frag->size;
+		proc->frag_block->flags |=
+			(frag->flags &
+			 (SQFS_BLK_DONT_COMPRESS | SQFS_BLK_ALIGN));
+	}
+
+	if (proc->frag_tbl != NULL) {
+		err = SQFS_ERROR_ALLOC;
+		chunk = calloc(1, sizeof(*chunk));
+		if (chunk == NULL)
+			goto fail;
+
+		chunk->index = index;
+		chunk->offset = offset;
+		chunk->size = frag->size;
+		chunk->hash = frag->checksum;
+
+		proc->current_frag = frag;
+		proc->fblk_lookup_error = 0;
+		entry = hash_table_insert_pre_hashed(proc->frag_ht, chunk->hash,
+						     chunk, chunk);
+		proc->current_frag = NULL;
+
+		if (proc->fblk_lookup_error != 0) {
+			err = proc->fblk_lookup_error;
+			goto fail;
+		}
+
+		if (entry == NULL)
+			goto fail;
+	}
+
+	if (frag->inode != NULL)
+		sqfs_inode_set_frag_location(*(frag->inode), index, offset);
+
+	if (frag != proc->frag_block)
+		release_old_block(proc, frag);
+
+	proc->stats.actual_frag_count += 1;
+	return 0;
+fail:
+	free(chunk);
+	if (frag != proc->frag_block)
+		release_old_block(proc, frag);
+	return err;
+}
+
+static void store_io_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
+{
+	sqfs_block_t *prev = NULL, *it = proc->io_queue;
+
+	while (it != NULL && (it->io_seq_num < blk->io_seq_num)) {
+		prev = it;
+		it = it->next;
+	}
+
+	if (prev == NULL) {
+		proc->io_queue = blk;
+	} else {
+		prev->next = blk;
+	}
+
+	blk->next = it;
+}
+
+int dequeue_block(sqfs_block_processor_t *proc)
+{
+	size_t backlog_old = proc->backlog;
+	sqfs_block_t *blk;
+	int status;
+
+	do {
+		while (proc->io_queue != NULL) {
+			if (proc->io_queue->io_seq_num != proc->io_deq_seq_num)
+				break;
+
+			blk = proc->io_queue;
+			proc->io_queue = blk->next;
+			proc->io_deq_seq_num += 1;
+
+			status = process_completed_block(proc, blk);
+			if (status != 0)
+				return status;
+		}
+
+		if (proc->backlog < backlog_old)
+			break;
+
+		if ((proc->backlog == 1) &&
+		    (proc->frag_block != NULL || proc->blk_current != NULL)) {
+			break;
+		}
+
+		if ((proc->backlog == 2) &&
+		    proc->frag_block != NULL && proc->blk_current != NULL) {
+			break;
+		}
+
+		blk = proc->pool->dequeue(proc->pool);
+
+		if (blk == NULL) {
+			status = proc->pool->get_status(proc->pool);
+			return status ? status : SQFS_ERROR_INTERNAL;
+		}
+
+		if (blk->flags & SQFS_BLK_IS_FRAGMENT) {
+			status = process_completed_fragment(proc, blk);
+			if (status != 0)
+				return status;
+		} else {
+			if (!(blk->flags & SQFS_BLK_FRAGMENT_BLOCK) ||
+			    (blk->flags & BLK_FLAG_MANUAL_SUBMISSION)) {
+				blk->io_seq_num = proc->io_seq_num++;
+			}
+
+			store_io_block(proc, blk);
+		}
+	} while (proc->backlog >= backlog_old);
+
+	return 0;
+}
diff --git a/lib/sqfs/src/block_processor/block_processor.c b/lib/sqfs/src/block_processor/block_processor.c
new file mode 100644
index 0000000..d607437
--- /dev/null
+++ b/lib/sqfs/src/block_processor/block_processor.c
@@ -0,0 +1,358 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * block_processor.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "internal.h"
+
+static int process_block(void *userptr, void *workitem)
+{
+	worker_data_t *worker = userptr;
+	sqfs_block_t *block = workitem;
+	sqfs_s32 ret;
+
+	if (block->size == 0)
+		return 0;
+
+	if (!(block->flags & SQFS_BLK_IGNORE_SPARSE) &&
+	    is_memory_zero(block->data, block->size)) {
+		block->flags |= SQFS_BLK_IS_SPARSE;
+		return 0;
+	}
+
+	if (block->flags & SQFS_BLK_DONT_HASH) {
+		block->checksum = 0;
+	} else {
+		block->checksum = xxh32(block->data, block->size);
+	}
+
+	if (block->flags & (SQFS_BLK_IS_FRAGMENT | SQFS_BLK_DONT_COMPRESS))
+		return 0;
+
+	ret = worker->cmp->do_block(worker->cmp, block->data, block->size,
+				    worker->scratch, worker->scratch_size);
+	if (ret < 0)
+		return ret;
+
+	if (ret > 0) {
+		memcpy(block->data, worker->scratch, ret);
+		block->size = ret;
+		block->flags |= SQFS_BLK_IS_COMPRESSED;
+	}
+	return 0;
+}
+
+static int load_frag_block(sqfs_block_processor_t *proc, sqfs_u32 index)
+{
+	sqfs_fragment_t info;
+	size_t size;
+	int ret;
+
+	if (proc->cached_frag_blk == NULL) {
+		size = sizeof(*proc->cached_frag_blk);
+
+		proc->cached_frag_blk = alloc_flex(size, 1,
+						   proc->max_block_size);
+
+		if (proc->cached_frag_blk == NULL)
+			return SQFS_ERROR_ALLOC;
+	} else {
+		if (proc->cached_frag_blk->index == index)
+			return 0;
+	}
+
+	ret = sqfs_frag_table_lookup(proc->frag_tbl, index, &info);
+	if (ret != 0)
+		return ret;
+
+	size = SQFS_ON_DISK_BLOCK_SIZE(info.size);
+	if (size > proc->max_block_size)
+		return SQFS_ERROR_CORRUPTED;
+
+	if (SQFS_IS_BLOCK_COMPRESSED(info.size)) {
+		ret = proc->file->read_at(proc->file, info.start_offset,
+					  proc->scratch, size);
+		if (ret != 0)
+			return ret;
+
+		ret = proc->uncmp->do_block(proc->uncmp, proc->scratch, size,
+					    proc->cached_frag_blk->data,
+					    proc->max_block_size);
+		if (ret <= 0)
+			return ret ? ret : SQFS_ERROR_OVERFLOW;
+
+		size = ret;
+	} else {
+		ret = proc->file->read_at(proc->file, info.start_offset,
+					  proc->cached_frag_blk->data, size);
+		if (ret != 0)
+			return ret;
+	}
+
+	proc->cached_frag_blk->size = size;
+	proc->cached_frag_blk->index = index;
+	return 0;
+}
+
+static bool chunk_info_equals(void *user, const void *k, const void *c)
+{
+	const chunk_info_t *key = k, *cmp = c;
+	sqfs_block_processor_t *proc = user;
+	sqfs_block_t *it;
+	int ret;
+
+	if (key->size != cmp->size || key->hash != cmp->hash)
+		return false;
+
+	if (proc->uncmp == NULL || proc->file == NULL)
+		return true;
+
+	if (proc->current_frag == NULL || proc->frag_tbl == NULL)
+		return true;
+
+	if (proc->fblk_lookup_error != 0)
+		return false;
+
+	for (it = proc->fblk_in_flight; it != NULL; it = it->next) {
+		if (it->index == cmp->index)
+			break;
+	}
+
+	if (it == NULL && proc->frag_block != NULL) {
+		if (proc->frag_block->index == cmp->index)
+			it = proc->frag_block;
+	}
+
+	if (it == NULL) {
+		ret = load_frag_block(proc, cmp->index);
+		if (ret != 0) {
+			proc->fblk_lookup_error = ret;
+			return false;
+		}
+
+		it = proc->cached_frag_blk;
+	}
+
+	if (cmp->offset >= it->size || (it->size - cmp->offset) < cmp->size) {
+		proc->fblk_lookup_error = SQFS_ERROR_CORRUPTED;
+		return false;
+	}
+
+	if (cmp->size != proc->current_frag->size) {
+		proc->fblk_lookup_error = SQFS_ERROR_CORRUPTED;
+		return false;
+	}
+
+	return memcmp(it->data + cmp->offset,
+		      proc->current_frag->data, cmp->size) == 0;
+}
+
+static void ht_delete_function(struct hash_entry *entry)
+{
+	free(entry->data);
+}
+
+static void free_block_list(sqfs_block_t *list)
+{
+	while (list != NULL) {
+		sqfs_block_t *it = list;
+		list = it->next;
+		free(it);
+	}
+}
+
+static void block_processor_destroy(sqfs_object_t *base)
+{
+	sqfs_block_processor_t *proc = (sqfs_block_processor_t *)base;
+
+	free(proc->frag_block);
+	free(proc->blk_current);
+	free(proc->cached_frag_blk);
+
+	free_block_list(proc->free_list);
+	free_block_list(proc->io_queue);
+	free_block_list(proc->fblk_in_flight);
+
+	if (proc->frag_ht != NULL)
+		hash_table_destroy(proc->frag_ht, ht_delete_function);
+
+	/* XXX: shut down the pool first before cleaning up the worker data */
+	if (proc->pool != NULL)
+		proc->pool->destroy(proc->pool);
+
+	while (proc->workers != NULL) {
+		worker_data_t *worker = proc->workers;
+		proc->workers = worker->next;
+
+		sqfs_drop(worker->cmp);
+		free(worker);
+	}
+
+	sqfs_drop(proc->frag_tbl);
+	sqfs_drop(proc->wr);
+	sqfs_drop(proc->file);
+	sqfs_drop(proc->uncmp);
+	free(proc);
+}
+
+int sqfs_block_processor_sync(sqfs_block_processor_t *proc)
+{
+	int ret;
+
+	for (;;) {
+		if (proc->backlog == 0)
+			break;
+
+		if ((proc->backlog == 1) &&
+		    (proc->frag_block != NULL || proc->blk_current != NULL)) {
+			break;
+		}
+
+		if ((proc->backlog == 2) &&
+		    proc->frag_block != NULL && proc->blk_current != NULL) {
+			break;
+		}
+
+		ret = dequeue_block(proc);
+		if (ret != 0)
+			return ret;
+	}
+
+	return 0;
+}
+
+int sqfs_block_processor_finish(sqfs_block_processor_t *proc)
+{
+	sqfs_block_t *blk;
+	int status;
+
+	status = sqfs_block_processor_sync(proc);
+	if (status != 0)
+		return status;
+
+	if (proc->frag_block != NULL) {
+		blk = proc->frag_block;
+		blk->next = NULL;
+		proc->frag_block = NULL;
+
+		blk->io_seq_num = proc->io_seq_num++;
+
+		status = enqueue_block(proc, blk);
+		if (status != 0)
+			return status;
+
+		status = sqfs_block_processor_sync(proc);
+	}
+
+	return status;
+}
+
+const sqfs_block_processor_stats_t
+*sqfs_block_processor_get_stats(const sqfs_block_processor_t *proc)
+{
+	return &proc->stats;
+}
+
+int sqfs_block_processor_create_ex(const sqfs_block_processor_desc_t *desc,
+				   sqfs_block_processor_t **out)
+{
+	size_t i, count, scratch_size = 0;
+	sqfs_block_processor_t *proc;
+	int ret;
+
+	if (desc->size != sizeof(sqfs_block_processor_desc_t))
+		return SQFS_ERROR_ARG_INVALID;
+
+	if (desc->file != NULL && desc->uncmp != NULL)
+		scratch_size = desc->max_block_size;
+
+	proc = alloc_flex(sizeof(*proc), 1, scratch_size);
+	if (proc == NULL)
+		return SQFS_ERROR_ALLOC;
+
+	sqfs_object_init(proc, block_processor_destroy, NULL);
+
+	proc->max_backlog = desc->max_backlog;
+	proc->max_block_size = desc->max_block_size;
+	proc->frag_tbl = sqfs_grab(desc->tbl);
+	proc->wr = sqfs_grab(desc->wr);
+	proc->file = sqfs_grab(desc->file);
+	proc->uncmp = sqfs_grab(desc->uncmp);
+	proc->stats.size = sizeof(proc->stats);
+
+	/* we need at least one current data block + one fragment block */
+	if (proc->max_backlog < 3)
+		proc->max_backlog = 3;
+
+	/* create the thread pool */
+	proc->pool = thread_pool_create(desc->num_workers, process_block);
+	if (proc->pool == NULL) {
+		ret = SQFS_ERROR_INTERNAL;
+		goto fail_pool;
+	}
+
+	/* create the worker compressors & scratch buffer */
+	count = proc->pool->get_worker_count(proc->pool);
+
+	for (i = 0; i < count; ++i) {
+		worker_data_t *worker = alloc_flex(sizeof(*worker), 1,
+						   desc->max_block_size);
+		if (worker == NULL) {
+			ret = SQFS_ERROR_ALLOC;
+			goto fail_pool;
+		}
+
+		worker->scratch_size = desc->max_block_size;
+		worker->next = proc->workers;
+		proc->workers = worker;
+
+		worker->cmp = sqfs_copy(desc->cmp);
+		if (worker->cmp == NULL) {
+			ret = SQFS_ERROR_ALLOC;
+			goto fail_pool;
+		}
+
+		proc->pool->set_worker_ptr(proc->pool, i, worker);
+	}
+
+	/* create the fragment hash table */
+	proc->frag_ht = hash_table_create(NULL, chunk_info_equals);
+	if (proc->frag_ht == NULL) {
+		ret = SQFS_ERROR_ALLOC;
+		goto fail_pool;
+	}
+
+	proc->frag_ht->user = proc;
+	*out = proc;
+	return 0;
+fail_pool:
+	block_processor_destroy((sqfs_object_t *)proc);
+	return ret;
+}
+
+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,
+						    sqfs_block_writer_t *wr,
+						    sqfs_frag_table_t *tbl)
+{
+	sqfs_block_processor_desc_t desc;
+	sqfs_block_processor_t *out;
+
+	memset(&desc, 0, sizeof(desc));
+	desc.size = sizeof(desc);
+	desc.max_block_size = max_block_size;
+	desc.num_workers = num_workers;
+	desc.max_backlog = max_backlog;
+	desc.cmp = cmp;
+	desc.wr = wr;
+	desc.tbl = tbl;
+
+	if (sqfs_block_processor_create_ex(&desc, &out) != 0)
+		return NULL;
+
+	return out;
+}
diff --git a/lib/sqfs/src/block_processor/frontend.c b/lib/sqfs/src/block_processor/frontend.c
new file mode 100644
index 0000000..e8a4207
--- /dev/null
+++ b/lib/sqfs/src/block_processor/frontend.c
@@ -0,0 +1,243 @@
+/* SPDX-License-Identifier: LGPL-3.0-or-later */
+/*
+ * frontend.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#define SQFS_BUILDING_DLL
+#include "internal.h"
+
+static int get_new_block(sqfs_block_processor_t *proc, sqfs_block_t **out)
+{
+	sqfs_block_t *blk;
+
+	while (proc->backlog >= proc->max_backlog) {
+		int ret = dequeue_block(proc);
+		if (ret != 0)
+			return ret;
+	}
+
+	if (proc->free_list != NULL) {
+		blk = proc->free_list;
+		proc->free_list = blk->next;
+	} else {
+		blk = malloc(sizeof(*blk) + proc->max_block_size);
+		if (blk == NULL)
+			return SQFS_ERROR_ALLOC;
+	}
+
+	memset(blk, 0, sizeof(*blk));
+	*out = blk;
+
+	proc->backlog += 1;
+	return 0;
+}
+
+static int add_sentinel_block(sqfs_block_processor_t *proc)
+{
+	sqfs_block_t *blk;
+	int ret;
+
+	ret = get_new_block(proc, &blk);
+	if (ret != 0)
+		return ret;
+
+	blk->inode = proc->inode;
+	blk->flags = proc->blk_flags | SQFS_BLK_LAST_BLOCK;
+
+	return enqueue_block(proc, blk);
+}
+
+int enqueue_block(sqfs_block_processor_t *proc, sqfs_block_t *blk)
+{
+	int status;
+
+	if ((blk->flags & SQFS_BLK_FRAGMENT_BLOCK) &&
+	    proc->file != NULL && proc->uncmp != NULL) {
+		sqfs_block_t *copy = alloc_flex(sizeof(*copy), 1, blk->size);
+
+		if (copy == NULL)
+			return SQFS_ERROR_ALLOC;
+
+		copy->size = blk->size;
+		copy->index = blk->index;
+		memcpy(copy->data, blk->data, blk->size);
+
+		copy->next = proc->fblk_in_flight;
+		proc->fblk_in_flight = copy;
+	}
+
+	if (proc->pool->submit(proc->pool, blk) != 0) {
+		status = proc->pool->get_status(proc->pool);
+
+		if (status == 0)
+			status = SQFS_ERROR_ALLOC;
+
+		blk->next = proc->free_list;
+		proc->free_list = blk;
+		return status;
+	}
+
+	return 0;
+}
+
+int sqfs_block_processor_begin_file(sqfs_block_processor_t *proc,
+				    sqfs_inode_generic_t **inode,
+				    void *user, sqfs_u32 flags)
+{
+	if (proc->begin_called)
+		return SQFS_ERROR_SEQUENCE;
+
+	if (flags & ~SQFS_BLK_USER_SETTABLE_FLAGS)
+		return SQFS_ERROR_UNSUPPORTED;
+
+	if (inode != NULL) {
+		(*inode) = calloc(1, sizeof(sqfs_inode_generic_t));
+		if ((*inode) == NULL)
+			return SQFS_ERROR_ALLOC;
+
+		(*inode)->base.type = SQFS_INODE_FILE;
+		sqfs_inode_set_frag_location(*inode, 0xFFFFFFFF, 0xFFFFFFFF);
+	}
+
+	proc->begin_called = true;
+	proc->inode = inode;
+	proc->blk_flags = flags | SQFS_BLK_FIRST_BLOCK;
+	proc->blk_index = 0;
+	proc->user = user;
+	return 0;
+}
+
+int sqfs_block_processor_append(sqfs_block_processor_t *proc, const void *data,
+				size_t size)
+{
+	sqfs_block_t *new;
+	sqfs_u64 filesize;
+	size_t diff;
+	int err;
+
+	if (!proc->begin_called)
+		return SQFS_ERROR_SEQUENCE;
+
+	if (proc->inode != NULL) {
+		sqfs_inode_get_file_size(*(proc->inode), &filesize);
+		sqfs_inode_set_file_size(*(proc->inode), filesize + size);
+	}
+
+	while (size > 0) {
+		if (proc->blk_current == NULL) {
+			err = get_new_block(proc, &new);
+			if (err != 0)
+				return err;
+
+			proc->blk_current = new;
+			proc->blk_current->flags = proc->blk_flags;
+			proc->blk_current->inode = proc->inode;
+			proc->blk_current->user = proc->user;
+			proc->blk_current->index = proc->blk_index++;
+			proc->blk_flags &= ~SQFS_BLK_FIRST_BLOCK;
+		}
+
+		diff = proc->max_block_size - proc->blk_current->size;
+
+		if (diff == 0) {
+			err = enqueue_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;
+
+		proc->stats.input_bytes_read += diff;
+	}
+
+	if (proc->blk_current->size == proc->max_block_size) {
+		err = enqueue_block(proc, proc->blk_current);
+		proc->blk_current = NULL;
+
+		if (err)
+			return err;
+	}
+
+	return 0;
+}
+
+int sqfs_block_processor_end_file(sqfs_block_processor_t *proc)
+{
+	int err;
+
+	if (!proc->begin_called)
+		return SQFS_ERROR_SEQUENCE;
+
+	if (proc->blk_current == NULL) {
+		if (!(proc->blk_flags & SQFS_BLK_FIRST_BLOCK)) {
+			err = add_sentinel_block(proc);
+			if (err)
+				return err;
+		}
+	} else {
+		if (proc->blk_flags & SQFS_BLK_DONT_FRAGMENT) {
+			proc->blk_current->flags |= SQFS_BLK_LAST_BLOCK;
+		} else {
+			if (!(proc->blk_current->flags &
+			      SQFS_BLK_FIRST_BLOCK)) {
+				err = add_sentinel_block(proc);
+				if (err)
+					return err;
+			}
+
+			proc->blk_current->flags |= SQFS_BLK_IS_FRAGMENT;
+		}
+
+		err = enqueue_block(proc, proc->blk_current);
+		proc->blk_current = NULL;
+
+		if (err)
+			return err;
+	}
+
+	proc->begin_called = false;
+	proc->inode = NULL;
+	proc->user = NULL;
+	proc->blk_flags = 0;
+	return 0;
+}
+
+int sqfs_block_processor_submit_block(sqfs_block_processor_t *proc, void *user,
+				      sqfs_u32 flags, const void *data,
+				      size_t size)
+{
+	sqfs_block_t *blk;
+	int ret;
+
+	if (proc->begin_called)
+		return SQFS_ERROR_SEQUENCE;
+
+	if (size > proc->max_block_size)
+		return SQFS_ERROR_OVERFLOW;
+
+	if (flags & ~SQFS_BLK_FLAGS_ALL)
+		return SQFS_ERROR_UNSUPPORTED;
+
+	ret = get_new_block(proc, &blk);
+	if (ret != 0)
+		return ret;
+
+	blk->flags = flags | BLK_FLAG_MANUAL_SUBMISSION;
+	blk->user = user;
+	blk->size = size;
+	memcpy(blk->data, data, size);
+
+	return enqueue_block(proc, blk);
+}
diff --git a/lib/sqfs/src/block_processor/internal.h b/lib/sqfs/src/block_processor/internal.h
new file mode 100644
index 0000000..0b2c88d
--- /dev/null
+++ b/lib/sqfs/src/block_processor/internal.h
@@ -0,0 +1,115 @@
+/* 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/block_writer.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/hash_table.h"
+#include "util/threadpool.h"
+#include "util/util.h"
+
+#include <string.h>
+#include <stdlib.h>
+
+typedef struct {
+	sqfs_u32 index;
+	sqfs_u32 offset;
+	sqfs_u32 size;
+	sqfs_u32 hash;
+} chunk_info_t;
+
+enum {
+	BLK_FLAG_MANUAL_SUBMISSION = 0x10000000,
+	BLK_FLAG_INTERNAL = 0x10000000,
+};
+
+typedef struct sqfs_block_t {
+	struct sqfs_block_t *next;
+	sqfs_inode_generic_t **inode;
+
+	sqfs_u32 io_seq_num;
+	sqfs_u32 flags;
+	sqfs_u32 size;
+	sqfs_u32 checksum;
+
+	/* For data blocks: index within the inode.
+	   For fragment fragment blocks: fragment table index. */
+	sqfs_u32 index;
+
+	/* User data pointer */
+	void *user;
+
+	sqfs_u8 data[];
+} sqfs_block_t;
+
+typedef struct worker_data_t {
+	struct worker_data_t *next;
+	sqfs_compressor_t *cmp;
+
+	size_t scratch_size;
+	sqfs_u8 scratch[];
+} worker_data_t;
+
+struct sqfs_block_processor_t {
+	sqfs_object_t obj;
+
+	sqfs_frag_table_t *frag_tbl;
+	sqfs_block_t *frag_block;
+	sqfs_block_writer_t *wr;
+
+	sqfs_block_processor_stats_t stats;
+
+	sqfs_inode_generic_t **inode;
+	sqfs_block_t *blk_current;
+	sqfs_u32 blk_flags;
+	sqfs_u32 blk_index;
+	void *user;
+
+	struct hash_table *frag_ht;
+	sqfs_block_t *free_list;
+
+	size_t max_block_size;
+	size_t max_backlog;
+	size_t backlog;
+
+	bool begin_called;
+
+	sqfs_file_t *file;
+	sqfs_compressor_t *uncmp;
+
+	thread_pool_t *pool;
+	worker_data_t *workers;
+
+	sqfs_block_t *io_queue;
+	sqfs_u32 io_seq_num;
+	sqfs_u32 io_deq_seq_num;
+
+	sqfs_block_t *current_frag;
+	sqfs_block_t *cached_frag_blk;
+	sqfs_block_t *fblk_in_flight;
+	int fblk_lookup_error;
+
+	sqfs_u8 scratch[];
+};
+
+SQFS_INTERNAL int enqueue_block(sqfs_block_processor_t *proc,
+				sqfs_block_t *blk);
+
+SQFS_INTERNAL int dequeue_block(sqfs_block_processor_t *proc);
+
+#endif /* INTERNAL_H */