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| author | Milian Wolff <milian.wolff@kdab.com> | 2015-05-30 23:10:00 +0200 |
|---|---|---|
| committer | Marc Mutz <marc.mutz@kdab.com> | 2015-12-12 09:07:06 +0000 |
| commit | 6cc79ad9947bc353dbc7decd91c462c9b104cf92 (patch) | |
| tree | 17613f2d008e89bc6c5521ee6e51dba0df747ee4 /src/tools | |
| parent | b894dfe311bb90210af102a59b3a09f587bb7442 (diff) | |
Optimize moc: Preallocate space for list of preprocessed symbols.
Without this, the symbol list is frequently reallocated. The value
is a guestimate. It corresponds to a block of memory with the size
262144 * 3 * 8 byte = ca. 6.3 megabytes
on a 64 bit machine. Looking at the final size of the symbol list,
this seems to fit the common case nicely.
Change-Id: Ib546a1ea479f2c6d8ab57be783cdf630f9b54f77
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
Diffstat (limited to 'src/tools')
| -rw-r--r-- | src/tools/moc/preprocessor.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/src/tools/moc/preprocessor.cpp b/src/tools/moc/preprocessor.cpp index 590f17c24f..a47896d722 100644 --- a/src/tools/moc/preprocessor.cpp +++ b/src/tools/moc/preprocessor.cpp @@ -1222,6 +1222,10 @@ Symbols Preprocessor::preprocessed(const QByteArray &filename, QFile *file) // phase 3: preprocess conditions and substitute macros Symbols result; + // Preallocate some space to speed up the code below. + // The magic value was found by logging the final size + // and calculating an average when running moc over FOSS projects. + result.reserve(file->size() / 300000); preprocess(filename, result); mergeStringLiterals(&result); |