1 files changed, 87 insertions, 0 deletions
diff --git a/include/sqfs/meta_writer.h b/include/sqfs/meta_writer.h
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+++ b/include/sqfs/meta_writer.h
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+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * meta_writer.h
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#ifndef META_WRITER_H
+#define META_WRITER_H
+
+#include "config.h"
+
+#include "compress.h"
+#include "squashfs.h"
+#include "id_table.h"
+#include "fstree.h"
+
+typedef struct {
+	tree_node_t *node;
+	uint32_t block;
+	uint32_t index;
+} idx_ref_t;
+
+typedef struct {
+	size_t num_nodes;
+	size_t max_nodes;
+	idx_ref_t idx_nodes[];
+} dir_index_t;
+
+typedef struct meta_writer_t meta_writer_t;
+
+/* Create a meta data reader using a given compressor to compress data.
+   Internally prints error message to stderr on failure.
+   If keep_in_mem is true, the blocks are collected in memory and must
+   be explicitly flushed to disk using meta_write_write_to_file.
+*/
+meta_writer_t *meta_writer_create(int fd, compressor_t *cmp, bool keep_in_mem);
+
+void meta_writer_destroy(meta_writer_t *m);
+
+/* Compress and flush the currently unfinished block to disk. Returns 0 on
+   success, internally prints error message to stderr on failure */
+int meta_writer_flush(meta_writer_t *m);
+
+/* Returns 0 on success. Prints error message to stderr on failure. */
+int meta_writer_append(meta_writer_t *m, const void *data, size_t size);
+
+/* Query the current block start position and offset within the block */
+void meta_writer_get_position(const meta_writer_t *m, uint64_t *block_start,
+			      uint32_t *offset);
+
+/* Reset all internal state, including the current block start position. */
+void meta_writer_reset(meta_writer_t *m);
+
+/* If created with keep_in_mem true, write the collected blocks to disk.
+   Does not flush the current block. Writes error messages to stderr and
+   returns non-zero on failure. */
+int meta_write_write_to_file(meta_writer_t *m);
+
+/*
+  High level helper function that writes squashfs directory entries to
+  a meta data writer.
+
+  The dir_info_t structure is used to generate the listing and updated
+  accordingly (such as writing back the header position and total size).
+  A directory index is created on the fly and returned in *index.
+  A single free() call is sufficient.
+
+  Returns 0 on success. Prints error messages to stderr on failure.
+ */
+int meta_writer_write_dir(meta_writer_t *dm, dir_info_t *dir,
+			  dir_index_t **index);
+
+/*
+  High level helper function to serialize a tree_node_t to a squashfs inode
+  and write it to a meta data writer.
+
+  The inode is written to `im`. If it is a directory node, the directory
+  contents are written to `dm` using meta_writer_write_dir. The given
+  id_table_t is used to store the uid and gid on the fly and write the
+  coresponding indices to the inode structure.
+
+  Returns 0 on success. Prints error messages to stderr on failure.
+ */
+int meta_writer_write_inode(fstree_t *fs, id_table_t *idtbl, meta_writer_t *im,
+			    meta_writer_t *dm, tree_node_t *node);
+
+#endif /* META_WRITER_H */