1 files changed, 87 insertions, 0 deletions
diff --git a/lib/sqfshelper/data_reader_dump.c b/lib/sqfshelper/data_reader_dump.c
new file mode 100644
index 0000000..23cd482
--- /dev/null
+++ b/lib/sqfshelper/data_reader_dump.c
@@ -0,0 +1,87 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * data_reader_dump.c
+ *
+ * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at>
+ */
+#include "config.h"
+
+#include "sqfs/block_processor.h"
+#include "data_reader.h"
+#include "highlevel.h"
+#include "util.h"
+
+#include <stdlib.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdio.h>
+
+int data_reader_dump(data_reader_t *data, const sqfs_inode_generic_t *inode,
+		     int outfd, size_t block_size, bool allow_sparse)
+{
+	sqfs_block_t *blk;
+	uint64_t filesz;
+	size_t i, diff;
+	int err;
+
+	if (inode->base.type == SQFS_INODE_EXT_FILE) {
+		filesz = inode->data.file_ext.file_size;
+	} else {
+		filesz = inode->data.file.file_size;
+	}
+
+	if (allow_sparse && ftruncate(outfd, filesz))
+		goto fail_sparse;
+
+	for (i = 0; i < inode->num_file_blocks; ++i) {
+		if (SQFS_IS_SPARSE_BLOCK(inode->block_sizes[i]) &&
+		    allow_sparse) {
+			if (filesz < block_size) {
+				diff = filesz;
+				filesz = 0;
+			} else {
+				diff = block_size;
+				filesz -= block_size;
+			}
+
+			if (lseek(outfd, diff, SEEK_CUR) == (off_t)-1)
+				goto fail_sparse;
+		} else {
+			err = data_reader_get_block(data, inode, i, &blk);
+			if (err) {
+				fprintf(stderr, "error reading "
+					"data block: %d\n", err);
+				return -1;
+			}
+
+			if (write_data("writing uncompressed block",
+				       outfd, blk->data, blk->size)) {
+				free(blk);
+				return -1;
+			}
+
+			free(blk);
+			filesz -= blk->size;
+		}
+	}
+
+	if (filesz > 0) {
+		if (data_reader_get_fragment(data, inode, &blk)) {
+			fputs("error reading fragment block", stderr);
+			return -1;
+		}
+
+		if (write_data("writing uncompressed fragment", outfd,
+			       blk->data, blk->size)) {
+			free(blk);
+			return -1;
+		}
+
+		free(blk);
+	}
+
+	return 0;
+fail_sparse:
+	perror("creating sparse output file");
+	return -1;
+}