Many developers use functionality in their editors that allows for quick
syntax checks, including warning about questionable constructs. This
functionality allows rapid development with fewer errors. However, such
functionality generally does not allow the specification of
project-specific defines or command-line options.
Since the SHA1_HEADER include is not defined in such a case,
developers see spurious errors when using these tools. Furthermore,
there are known implementations of "cc" whose '#include' is unhappy
with this construct.
Instead of using SHA1_HEADER, create a hash.h header and use #if
and #elif to select the desired header. Have the Makefile pass an
appropriate option to help the header select the right implementation to
use.
[jc: make BLK_SHA1 the fallback default as discussed on list,
e.g. <20170314201424.vccij5z2ortq4a4o@sigill.intra.peff.net>; also
remove SHA1_HEADER and SHA1_HEADER_SQ that are no longer used].
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reviewed-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This avoids unnecessary re-allocations and reinsertions. On webkit.git
(i.e. about 182k inserts to the name hash table), this reduces about
100ms out of 3s user time.
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
For the find_exact_renames() function, this allows us to pass the
diff_options structure pointer to the low-level routines. We will use
that to distinguish between the "rename" and "copy" cases.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This is in an effort to make the source index of 'unpack_trees()' as
being const, and thus making the compiler help us verify that we only
access it for reading.
The constification also extended to some of the hashing helpers that get
called indirectly.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This implements a smarter rename detector for exact renames, which
rather than doing a pairwise comparison (time O(m*n)) will just hash the
files into a hash-table (size O(n+m)), and only do pairwise comparisons
to renames that have the same hash (time O(n+m) except for unrealistic
hash collissions, which we just cull aggressively).
Admittedly the exact rename case is not nearly as interesting as the
generic case, but it's an important case none-the-less. A similar general
approach should work for the generic case too, but even then you do need
to handle the exact renames/copies separately (to avoid the inevitable
added cost factor that comes from the _size_ of the file), so this is
worth doing.
In the expectation that we will indeed do the same hashing trick for the
general rename case, this code uses a generic hash-table implementation
that can be used for other things too. In fact, we might be able to
consolidate some of our existing hash tables with the new generic code
in hash.[ch].
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
