This is copy-pasted from the gzip utility, along with its existing TODO.
This is currently only needed by that utility, but this gives us API
symmetry with GzipDecompressor, and helps ensure we won't end up in a
situation where only one utility receives optimizations that should be
received by all interested parties.
We currently mix normal and bit streams during GZIP decompression, where
the latter is a wrapper around the former. This isn't causing issues now
as the underlying bit stream buffer is a byte, so the normal stream can
pick up where the bit stream left off.
In order to increase the size of that buffer though, the normal stream
will not be able to assume it can resume reading after the bit stream.
The buffer can easily contain more bits than it was meant to read, so
when the normal stream resumes, there may be N bits leftover in the bit
stream that the normal stream was meant to read.
To avoid weird behavior when mixing streams, this changes the GZIP
decompressor to always read from a bit stream.
Similar to POSIX read, the basic read and write functions of AK::Stream
do not have a lower limit of how much data they read or write (apart
from "none at all").
Rename the functions to "read some [data]" and "write some [data]" (with
"data" being omitted, since everything here is reading and writing data)
to make them sufficiently distinct from the functions that ensure to
use the entire buffer (which should be the go-to function for most
usages).
No functional changes, just a lot of new FIXMEs.
`Stream` will be qualified as `AK::Stream` until we remove the
`Core::Stream` namespace. `IODevice` now reuses the `SeekMode` that is
defined by `SeekableStream`, since defining its own would require us to
qualify it with `AK::SeekMode` everywhere.
We don't have anything fallible in there yet, but we will soon switch
the seekback buffer to the new `CircularBuffer`, which has a fallible
constructor.
We have to do the same for the internal `GzipDecompressor::Member`
class, as it needs to construct a `DeflateCompressor` from its received
stream.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
We now read the header into a temporary header byte array that is used
as the header once its filled up by the input stream, instead of just
ending the stream if we are out of bytes mid header.
This commit makes read short-circuit if its input stream errored,
as well as propagate error handling to wrapped sub streams, similarly
to DeflateDecompressor.
This commit implements a stream compressor for the gzip
specification (RFC 1952), which is essentially a thin
wrapper around the DEFLATE compression format.
This commit removes the only 3rd party library (and its usages)
in serenity: puff, which is used for deflate decompression. and
replaces it with the existing original serenity implementation
in LibCompress. :^)
