2fd990b386
The zlib convenience API we've been using so far has two problems: - On Windows-64, where sizeof(long) == 4, the use of ulong for sizes meant that we could not compress data compressable on other 64-bit platforms (Unix). While zstream also uses ulong, being a stream API, it allows feeding data in chunks. The total_in and total_out members are only required for gzip compression and are otherwise just informational. They're unsigned, so their overflow does not cause UB. In summary, using zstream + deflate() allows us to compress more than 4GiB of data even on Windows-64. - On all platforms, we always allocated the output buffer in such a way as to accommodate the pathological case of random, incompressible data, so the output buffer was larger than the input. Using zstream + deflate(), we can start with a smaller buffer, then let zlib pick up where it left off when it ran out of output buffer space, saving memory in the common case that compression meaningfully reduces the size. To avoid the first few rounds of reallocations, we continue to use zlib's compressBound() for input less than 256KiB. This completely fixes the compression side of QTBUG-106542 and QTBUG-104972. Pick-to: 6.4 6.3 6.2 Fixes: QTBUG-104972 Fixes: QTBUG-106542 Change-Id: Ia7e6c38403906b35462480fd611b482f05a5c59c Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org> Reviewed-by: Thiago Macieira <thiago.macieira@intel.com> Reviewed-by: Edward Welbourne <edward.welbourne@qt.io> |
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| .. | ||
| auto | ||
| baseline | ||
| benchmarks | ||
| global | ||
| libfuzzer | ||
| manual | ||
| shared | ||
| testserver | ||
| CMakeLists.txt | ||
| README | ||
This directory contains autotests and benchmarks based on Qt Test. In order
to run the autotests reliably, you need to configure a desktop to match the
test environment that these tests are written for.
Linux X11:
* The user must be logged in to an active desktop; you can't run the
autotests without a valid DISPLAY that allows X11 connections.
* The tests are run against a KDE3 or KDE4 desktop.
* Window manager uses "click to focus", and not "focus follows mouse". Many
tests move the mouse cursor around and expect this to not affect focus
and activation.
* Disable "click to activate", i.e., when a window is opened, the window
manager should automatically activate it (give it input focus) and not
wait for the user to click the window.