// Generates an index from a reader
// This is mostly a utility function to avoid being overly verbose in tests that need
// an index to work, but don't want to construct one by hand in order to avoid the dependencies
// obviously this means that those tests are likely to fail if there are issues with any of the other
// modules, which is not ideal.
// TODO: move to util?
func BuildChecksumIndex(check *filechecksum.FileChecksumGenerator, r io.Reader) (
fcheck []byte,
i *index.ChecksumIndex,
lookup filechecksum.ChecksumLookup,
err error,
) {
b := bytes.NewBuffer(nil)
fcheck, err = check.GenerateChecksums(r, b)
if err != nil {
return
}
weakSize := check.WeakRollingHash.Size()
strongSize := check.GetStrongHash().Size()
readChunks, err := chunks.LoadChecksumsFromReader(b, weakSize, strongSize)
if err != nil {
return
}
i = index.MakeChecksumIndex(readChunks)
lookup = chunks.StrongChecksumGetter(readChunks)
return
}
func readIndex(r io.Reader, blocksize uint) (
i *index.ChecksumIndex,
checksumLookup filechecksum.ChecksumLookup,
blockCount uint,
err error,
) {
generator := filechecksum.NewFileChecksumGenerator(blocksize)
readChunks, e := chunks.LoadChecksumsFromReader(
r,
generator.WeakRollingHash.Size(),
generator.StrongHash.Size(),
)
err = e
if err != nil {
return
}
checksumLookup = chunks.StrongChecksumGetter(readChunks)
i = index.MakeChecksumIndex(readChunks)
blockCount = uint(len(readChunks))
return
}