The use of ReadAtOffset is meant to allow concurrent access
to the zip archive once it has been loaded. There were places
where this was the case, and some places that did a seek + read
combination, which could lead to data races.
NOTE: On Windows, we are not using pread as the implementation of
ReadAtOffset, therefore the guarantees on Windows are weaker.
On Linux, pread allows the file descriptor to be read at a specific
offset without changing the read pointer. This allows inherited fd's
and duped fds to be read concurrently.
On Windows, we use the ReadFile API, which allows for an atomic seek +
read operation, but modifies the read pointer. This means that any mix
use of ReadAtOffset and Read will have races. Just using ReadAtOffset is
safe.
For the Windows case, this is fine as the libziparchive code now only
uses ReadAtOffset.
Bug: 62184114
Bug: 62101783
Test: make ziparchive-tests (existing tests pass)
Change-Id: Ia7f9a30af2216682cdd9d578d26e84bc46773bb9
By forward-declaring zstream, we don't need to re-export zlib headers.
Bug: 37342627
Test: build
Test: BOARD_VNDK_VERSION=current m -j dumpstate (or any other module
using libziparchive)
Change-Id: Ia69e5d459c79878d491cfe4ca21a7cc8fed4a5d8
libziparchive headers are moved from the global include directory
(/system/core/include) to the local directory inside libziparchive.
Note: /system/core/include/ziparchive still exists as a symlink to
libarchive/include/ziparchive. This will be removed when there is no
header-only dependency to libziparchive.
Bug: 37342627
Test: build
Change-Id: I3631ffc2df7be8a064d64a625d10436090c3bb0f
