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author | Lee Clagett <code@leeclagett.com> | 2020-10-13 15:09:18 +0000 |
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committer | Lee Clagett <code@leeclagett.com> | 2020-10-13 15:09:18 +0000 |
commit | 249eae5f4aad8c90e4e0eae19268fbf74fe05783 (patch) | |
tree | fd4672980a4090fb666f8c003799cfff64537bf9 | |
parent | Merge pull request #6927 (diff) | |
download | monero-249eae5f4aad8c90e4e0eae19268fbf74fe05783.tar.xz |
Allow byte_stream->byte_slice conversion to shrink unused buffer space
-rw-r--r-- | contrib/epee/include/byte_slice.h | 2 | ||||
-rw-r--r-- | contrib/epee/src/byte_slice.cpp | 24 | ||||
-rw-r--r-- | tests/unit_tests/epee_utils.cpp | 4 |
3 files changed, 24 insertions, 6 deletions
diff --git a/contrib/epee/include/byte_slice.h b/contrib/epee/include/byte_slice.h index 6b79f6d92..18d60e088 100644 --- a/contrib/epee/include/byte_slice.h +++ b/contrib/epee/include/byte_slice.h @@ -112,7 +112,7 @@ namespace epee explicit byte_slice(std::string&& buffer); //! Convert `stream` into a slice with zero allocations. - explicit byte_slice(byte_stream&& stream) noexcept; + explicit byte_slice(byte_stream&& stream, bool shrink = true); byte_slice(byte_slice&& source) noexcept; ~byte_slice() noexcept = default; diff --git a/contrib/epee/src/byte_slice.cpp b/contrib/epee/src/byte_slice.cpp index faf7689be..453b63a4c 100644 --- a/contrib/epee/src/byte_slice.cpp +++ b/contrib/epee/src/byte_slice.cpp @@ -36,6 +36,11 @@ #include "byte_slice.h" #include "byte_stream.h" +namespace +{ + const std::size_t page_size = 4096; +} + namespace epee { struct byte_slice_data @@ -173,16 +178,27 @@ namespace epee : byte_slice(adapt_buffer{}, std::move(buffer)) {} - byte_slice::byte_slice(byte_stream&& stream) noexcept + byte_slice::byte_slice(byte_stream&& stream, const bool shrink) : storage_(nullptr), portion_(stream.data(), stream.size()) { - if (stream.size()) + if (portion_.size()) { - std::uint8_t* const data = stream.take_buffer().release() - sizeof(raw_byte_slice); + byte_buffer buf; + if (shrink && page_size <= stream.available()) + { + buf = byte_buffer_resize(stream.take_buffer(), portion_.size()); + if (!buf) + throw std::bad_alloc{}; + portion_ = {buf.get(), portion_.size()}; + } + else // no need to shrink buffer + buf = stream.take_buffer(); + + std::uint8_t* const data = buf.release() - sizeof(raw_byte_slice); new (data) raw_byte_slice{}; storage_.reset(reinterpret_cast<raw_byte_slice*>(data)); } - else + else // empty stream portion_ = nullptr; } diff --git a/tests/unit_tests/epee_utils.cpp b/tests/unit_tests/epee_utils.cpp index b365cad86..0a1f0d3de 100644 --- a/tests/unit_tests/epee_utils.cpp +++ b/tests/unit_tests/epee_utils.cpp @@ -1090,11 +1090,13 @@ TEST(ByteStream, ToByteSlice) epee::byte_stream stream; + stream.reserve(128*1024); stream.write(source); EXPECT_EQ(sizeof(source), stream.size()); + EXPECT_EQ(128*1024, stream.capacity()); EXPECT_TRUE(equal(source, byte_span{stream.data(), stream.size()})); - const epee::byte_slice slice{std::move(stream)}; + const epee::byte_slice slice{std::move(stream), true}; EXPECT_EQ(0u, stream.size()); EXPECT_EQ(0u, stream.available()); EXPECT_EQ(0u, stream.capacity()); |