Re: [libvirt] [PATCH 1/4] storage: factor out large integer reads

This makes code easier to read, by avoiding lines longer than 80 columns and removing the repetition from the callers. * src/util/virstoragefile.c (virRead64BE, virRead64LE) (virRead32BE, virRead32LE): New helper functions. (qedGetHeaderUL, qedGetHeaderULL): Delete in favor of more generic name. (qcow2GetBackingStoreFormat, qcowXGetBackingStore) (qedGetBackingStore, virStorageFileMatchesVersion) (virStorageFileGetMetadataInternal): Use them. --- src/util/virstoragefile.c | 159 +++++++++++++++++++++------------------------- 1 file changed, 72 insertions(+), 87 deletions(-) diff --git a/src/util/virstoragefile.c b/src/util/virstoragefile.c index 6e2d61e..e7ab226 100644 --- a/src/util/virstoragefile.c +++ b/src/util/virstoragefile.c @@ -208,6 +208,58 @@ static struct FileTypeInfo const fileTypeInfo[] = { }; verify(ARRAY_CARDINALITY(fileTypeInfo) == VIR_STORAGE_FILE_LAST); +/* Read 8 bytes at BUF as a big-endian 64-bit number. Caller is + responsible to avoid reading beyond array bounds. */ +static unsigned long long +virRead64BE(const unsigned char *buf) +{ + return (((uint64_t)buf[0] << 56) | + ((uint64_t)buf[1] << 48) | + ((uint64_t)buf[2] << 40) | + ((uint64_t)buf[3] << 32) | + ((uint64_t)buf[4] << 24) | + ((uint64_t)buf[5] << 16) | + ((uint64_t)buf[6] << 8) | + (uint64_t)buf[7]); +} + +/* Read 8 bytes at BUF as a little-endian 64-bit number. Caller is + responsible to avoid reading beyond array bounds. */ +static unsigned long long +virRead64LE(const unsigned char *buf) +{ + return ((uint64_t)buf[0] | + ((uint64_t)buf[1] << 8) | + ((uint64_t)buf[2] << 16) | + ((uint64_t)buf[3] << 24) | + ((uint64_t)buf[4] << 32) | + ((uint64_t)buf[5] << 40) | + ((uint64_t)buf[6] << 48) | + ((uint64_t)buf[7] << 56)); +} + +/* Read 4 bytes at BUF as a big-endian 32-bit number. Caller is + responsible to avoid reading beyond array bounds. */ +static unsigned int +virRead32BE(const unsigned char *buf) +{ + return ((buf[0] << 24) | + (buf[1] << 16) | + (buf[2] << 8) | + buf[3]); +} + +/* Read 4 bytes at BUF as a little-endian 32-bit number. Caller is + responsible to avoid reading beyond array bounds. */ +static unsigned int +virRead32LE(const unsigned char *buf) +{ + return (buf[0] | + (buf[1] << 8) | + (buf[2] << 16) | + (buf[3] << 24)); +}