zdelta FAQ
- Can zdelta handle large
files?
- Can zdelta sliding windows be larger than 64kb?
- Is zdelta in-place?
- Does zdelta support streaming?
- How is the multi reference support in
zdelta-2.0 implemented?
- Can I use zdelta together with the zlib
library?
Although zdelta can compress and decompress correctly very large files, it
could sometimes have poor performance on files larger
than 100kb. The problem stems from the fact that for efficiency, zdelta
computes the difference between the reference
and the target file using only 64kb windows at a time. Currently the library
employs a simple window synchronization/movement
technique. As a result it is possible that the windows loose
synchronization. In such cases zdelta will act as a conventional
LZ77 compressor.
We are currently working on resolving this issue.
No, for variety of reasons the zdelta windows can not be larger than 64kb.
No, zdelta does not provide in-place decompression yet.
Currently the zdelta library supports streaming only on the target file, the
reference file(s) should still be available at the start
of the compression/decompression process. Additional interfaces for
streaming on the reference data will be provided in the
near future.
zdelta places 64kb windows in any of the reference files and tries to find
the longest possible match searching all of the
windows. The multi reference file support is NOT implemented by
concatenating the reference files and running zdelta with
with one reference file!
Yes, all global functions in zdelta have a prefix "zd_" added to their names to resolve name conflicts with
the zlib library.
Copyright © Dimitre Trendafilov 2002.
dtrend01@utopia.poly.edu