Add file API stub to sqfs data writer

Basically move the state tracking from the old data writer over to
the new one.

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

5 files changed, 136 insertions, 25 deletions

diff --git a/lib/sqfs/Makemodule.am b/lib/sqfs/Makemodule.am
index 36a8cc8..a474423 100644
--- a/lib/sqfs/Makemodule.am
+++ b/lib/sqfs/Makemodule.am
@@ -21,6 +21,7 @@ libsquashfs_la_SOURCES += lib/sqfs/inode.c lib/sqfs/data_writer/fragment.c
 libsquashfs_la_SOURCES += lib/sqfs/data_writer/block.c lib/sqfs/io.c
 libsquashfs_la_SOURCES += lib/sqfs/data_writer/internal.h lib/sqfs/data_reader.c
 libsquashfs_la_SOURCES += lib/sqfs/data_writer/common.c
+libsquashfs_la_SOURCES += lib/sqfs/data_writer/fileapi.c
 libsquashfs_la_CPPFLAGS = $(AM_CPPFLAGS)
 libsquashfs_la_CFLAGS = $(AM_CFLAGS) $(PTHREAD_CFLAGS) $(ZLIB_CFLAGS)
 libsquashfs_la_CFLAGS += $(XZ_CFLAGS) $(LZO_CFLAGS) $(LZ4_CFLAGS)
diff --git a/lib/sqfs/data_writer/fileapi.c b/lib/sqfs/data_writer/fileapi.c
new file mode 100644
index 0000000..b78d012
--- /dev/null
+++ b/lib/sqfs/data_writer/fileapi.c
@@ -0,0 +1,101 @@
+/* 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 add_sentinel_block(sqfs_data_writer_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 data_writer_enqueue(proc, blk);
+}
+
+int sqfs_data_writer_begin_file(sqfs_data_writer_t *proc,
+				sqfs_inode_generic_t *inode, uint32_t 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;
+	proc->blk_index = 0;
+	proc->had_fragment = false;
+	return 0;
+}
+
+int sqfs_data_writer_enqueue(sqfs_data_writer_t *proc, sqfs_block_t *block)
+{
+	int err;
+
+	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->block_sizes[block->index] = 0;
+		free(block);
+		return 0;
+	}
+
+	if (block->size < proc->max_block_size) {
+		if (block->index > 0) {
+			err = add_sentinel_block(proc);
+
+			if (err) {
+				free(block);
+				return err;
+			}
+		}
+
+		proc->had_fragment = true;
+		block->flags |= SQFS_BLK_IS_FRAGMENT;
+	} else {
+		if (block->index == 0)
+			block->flags |= SQFS_BLK_FIRST_BLOCK;
+
+		proc->inode->num_file_blocks += 1;
+	}
+
+	return data_writer_enqueue(proc, block);
+}
+
+int sqfs_data_writer_end_file(sqfs_data_writer_t *proc)
+{
+	int err;
+
+	if (proc->inode == NULL)
+		return test_and_set_status(proc, SQFS_ERROR_INTERNAL);
+
+	if (!proc->had_fragment && proc->inode->num_file_blocks > 0) {
+		err = add_sentinel_block(proc);
+		if (err)
+			return err;
+	}
+
+	proc->inode = NULL;
+	proc->blk_flags = 0;
+	proc->blk_index = 0;
+	proc->had_fragment = false;
+	return 0;
+}
diff --git a/lib/sqfs/data_writer/internal.h b/lib/sqfs/data_writer/internal.h
index 53ddc5f..9072c19 100644
--- a/lib/sqfs/data_writer/internal.h
+++ b/lib/sqfs/data_writer/internal.h
@@ -101,6 +101,12 @@ struct sqfs_data_writer_t {
 	const sqfs_block_hooks_t *hooks;
 	void *user_ptr;
 
+	/* file API */
+	sqfs_inode_generic_t *inode;
+	uint32_t blk_flags;
+	size_t blk_index;
+	bool had_fragment;
+
 	/* used only by workers */
 	size_t max_block_size;
 
@@ -138,4 +144,10 @@ SQFS_INTERNAL
 int data_writer_do_block(sqfs_block_t *block, sqfs_compressor_t *cmp,
 			 uint8_t *scratch, size_t scratch_size);
 
+SQFS_INTERNAL
+int test_and_set_status(sqfs_data_writer_t *proc, int status);
+
+SQFS_INTERNAL
+int data_writer_enqueue(sqfs_data_writer_t *proc, sqfs_block_t *block);
+
 #endif /* INTERNAL_H */
diff --git a/lib/sqfs/data_writer/pthread.c b/lib/sqfs/data_writer/pthread.c
index 3170c11..9c9b0a2 100644
--- a/lib/sqfs/data_writer/pthread.c
+++ b/lib/sqfs/data_writer/pthread.c
@@ -156,18 +156,6 @@ static void append_to_work_queue(sqfs_data_writer_t *proc,
 	pthread_cond_broadcast(&proc->queue_cond);
 }
 
-static int test_and_set_status(sqfs_data_writer_t *proc, int status)
-{
-	pthread_mutex_lock(&proc->mtx);
-	if (proc->status == 0) {
-		proc->status = status;
-	} else {
-		status = proc->status;
-	}
-	pthread_cond_broadcast(&proc->queue_cond);
-	return status;
-}
-
 static sqfs_block_t *try_dequeue(sqfs_data_writer_t *proc)
 {
 	sqfs_block_t *queue, *it, *prev;
@@ -260,16 +248,23 @@ static int process_done_queue(sqfs_data_writer_t *proc, sqfs_block_t *queue)
 	return status;
 }
 
-int sqfs_data_writer_enqueue(sqfs_data_writer_t *proc, sqfs_block_t *block)
+int test_and_set_status(sqfs_data_writer_t *proc, int status)
+{
+	pthread_mutex_lock(&proc->mtx);
+	if (proc->status == 0) {
+		proc->status = status;
+	} else {
+		status = proc->status;
+	}
+	pthread_cond_broadcast(&proc->queue_cond);
+	return status;
+}
+
+int data_writer_enqueue(sqfs_data_writer_t *proc, sqfs_block_t *block)
 {
 	sqfs_block_t *queue;
 	int status;
 
-	if (block->flags & ~SQFS_BLK_USER_SETTABLE_FLAGS) {
-		free(block);
-		return test_and_set_status(proc, SQFS_ERROR_UNSUPPORTED);
-	}
-
 	pthread_mutex_lock(&proc->mtx);
 	while (proc->backlog > proc->max_backlog && proc->status == 0)
 		pthread_cond_wait(&proc->done_cond, &proc->mtx);
diff --git a/lib/sqfs/data_writer/serial.c b/lib/sqfs/data_writer/serial.c
index 38dcc58..916f497 100644
--- a/lib/sqfs/data_writer/serial.c
+++ b/lib/sqfs/data_writer/serial.c
@@ -35,7 +35,15 @@ void sqfs_data_writer_destroy(sqfs_data_writer_t *proc)
 	data_writer_cleanup(proc);
 }
 
-int sqfs_data_writer_enqueue(sqfs_data_writer_t *proc, sqfs_block_t *block)
+int test_and_set_status(sqfs_data_writer_t *proc, int status)
+{
+	if (proc->status == 0)
+		proc->status = status;
+
+	return proc->status;
+}
+
+int data_writer_enqueue(sqfs_data_writer_t *proc, sqfs_block_t *block)
 {
 	sqfs_block_t *fragblk = NULL;
 
@@ -44,12 +52,6 @@ int sqfs_data_writer_enqueue(sqfs_data_writer_t *proc, sqfs_block_t *block)
 		return proc->status;
 	}
 
-	if (block->flags & ~SQFS_BLK_USER_SETTABLE_FLAGS) {
-		proc->status = SQFS_ERROR_UNSUPPORTED;
-		free(block);
-		return proc->status;
-	}
-
 	if (block->flags & SQFS_BLK_IS_FRAGMENT) {
 		block->checksum = crc32(0, block->data, block->size);