diff --git a/contrib/epee/include/byte_stream.h b/contrib/epee/include/byte_stream.h index 98f563ca9..42a9e1dd9 100644 --- a/contrib/epee/include/byte_stream.h +++ b/contrib/epee/include/byte_stream.h @@ -117,6 +117,9 @@ namespace epee check(more); } + //! Reset write position, but do not release internal memory. \post `size() == 0`. + void clear() noexcept { next_write_ = buffer_.get(); } + /*! Copy `length` bytes starting at `ptr` to end of stream. \throw std::range_error If exceeding max size_t value. \throw std::bad_alloc If allocation fails. */ diff --git a/tests/unit_tests/epee_utils.cpp b/tests/unit_tests/epee_utils.cpp index 0f91671a7..b365cad86 100644 --- a/tests/unit_tests/epee_utils.cpp +++ b/tests/unit_tests/epee_utils.cpp @@ -1117,6 +1117,47 @@ TEST(ByteStream, ToByteSlice) EXPECT_EQ(nullptr, empty_slice.data()); } +TEST(ByteStream, Clear) +{ + static constexpr const std::uint8_t source[] = + {0xde, 0xad, 0xbe, 0xef, 0xef}; + + epee::byte_stream stream{4}; + + EXPECT_EQ(4u, stream.increase_size()); + + EXPECT_EQ(nullptr, stream.data()); + EXPECT_EQ(nullptr, stream.tellp()); + EXPECT_EQ(0u, stream.size()); + EXPECT_EQ(0u, stream.available()); + EXPECT_EQ(0u, stream.capacity()); + + stream.clear(); + + EXPECT_EQ(nullptr, stream.data()); + EXPECT_EQ(nullptr, stream.tellp()); + EXPECT_EQ(0u, stream.size()); + EXPECT_EQ(0u, stream.available()); + EXPECT_EQ(0u, stream.capacity()); + + stream.write({source, 3}); + std::uint8_t const* const loc = stream.data(); + + EXPECT_EQ(loc, stream.data()); + EXPECT_EQ(loc + 3, stream.tellp()); + EXPECT_EQ(3u, stream.size()); + EXPECT_EQ(1u, stream.available()); + EXPECT_EQ(4u, stream.capacity()); + + stream.clear(); + + EXPECT_EQ(loc, stream.data()); + EXPECT_EQ(loc, stream.tellp()); + EXPECT_EQ(0u, stream.size()); + EXPECT_EQ(4u, stream.available()); + EXPECT_EQ(4u, stream.capacity()); +} + TEST(ToHex, String) { EXPECT_TRUE(epee::to_hex::string(nullptr).empty());