releasetools: Add unittest for common.GetSparseImage().
Add construct_sparse_image() to test_utils.py, which is a util function
to create sparse images. The new tests also partially cover the recent
changes that add 'incomplete' and 'uses_shard_blocks' tags.
Test: python -m unittest test_common
Change-Id: Ia15f5c4ad12423691216ebbad2c28f95c8427d7e
diff --git a/tools/releasetools/test_utils.py b/tools/releasetools/test_utils.py
index ec53731..e64355b 100644
--- a/tools/releasetools/test_utils.py
+++ b/tools/releasetools/test_utils.py
@@ -18,7 +18,11 @@
Utils for running unittests.
"""
+import os
import os.path
+import struct
+
+import common
def get_testdata_dir():
@@ -26,3 +30,67 @@
# The script dir is the one we want, which could be different from pwd.
current_dir = os.path.dirname(os.path.realpath(__file__))
return os.path.join(current_dir, 'testdata')
+
+
+def construct_sparse_image(chunks):
+ """Returns a sparse image file constructed from the given chunks.
+
+ From system/core/libsparse/sparse_format.h.
+ typedef struct sparse_header {
+ __le32 magic; // 0xed26ff3a
+ __le16 major_version; // (0x1) - reject images with higher major versions
+ __le16 minor_version; // (0x0) - allow images with higer minor versions
+ __le16 file_hdr_sz; // 28 bytes for first revision of the file format
+ __le16 chunk_hdr_sz; // 12 bytes for first revision of the file format
+ __le32 blk_sz; // block size in bytes, must be a multiple of 4 (4096)
+ __le32 total_blks; // total blocks in the non-sparse output image
+ __le32 total_chunks; // total chunks in the sparse input image
+ __le32 image_checksum; // CRC32 checksum of the original data, counting
+ // "don't care" as 0. Standard 802.3 polynomial,
+ // use a Public Domain table implementation
+ } sparse_header_t;
+
+ typedef struct chunk_header {
+ __le16 chunk_type; // 0xCAC1 -> raw; 0xCAC2 -> fill;
+ // 0xCAC3 -> don't care
+ __le16 reserved1;
+ __le32 chunk_sz; // in blocks in output image
+ __le32 total_sz; // in bytes of chunk input file including chunk header
+ // and data
+ } chunk_header_t;
+
+ Args:
+ chunks: A list of chunks to be written. Each entry should be a tuple of
+ (chunk_type, block_number).
+
+ Returns:
+ Filename of the created sparse image.
+ """
+ SPARSE_HEADER_MAGIC = 0xED26FF3A
+ SPARSE_HEADER_FORMAT = "<I4H4I"
+ CHUNK_HEADER_FORMAT = "<2H2I"
+
+ sparse_image = common.MakeTempFile(prefix='sparse-', suffix='.img')
+ with open(sparse_image, 'wb') as fp:
+ fp.write(struct.pack(
+ SPARSE_HEADER_FORMAT, SPARSE_HEADER_MAGIC, 1, 0, 28, 12, 4096,
+ sum(chunk[1] for chunk in chunks),
+ len(chunks), 0))
+
+ for chunk in chunks:
+ data_size = 0
+ if chunk[0] == 0xCAC1:
+ data_size = 4096 * chunk[1]
+ elif chunk[0] == 0xCAC2:
+ data_size = 4
+ elif chunk[0] == 0xCAC3:
+ pass
+ else:
+ assert False, "Unsupported chunk type: {}".format(chunk[0])
+
+ fp.write(struct.pack(
+ CHUNK_HEADER_FORMAT, chunk[0], 0, chunk[1], data_size + 12))
+ if data_size != 0:
+ fp.write(os.urandom(data_size))
+
+ return sparse_image