diff options
Diffstat (limited to 'src/streams.h')
| -rw-r--r-- | src/streams.h | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/src/streams.h b/src/streams.h index 8788343809..e346aa0a3f 100644 --- a/src/streams.h +++ b/src/streams.h @@ -756,15 +756,25 @@ public: } //! search for a given byte in the stream, and remain positioned on it - void FindByte(uint8_t ch) + void FindByte(std::byte byte) { + // For best performance, avoid mod operation within the loop. + size_t buf_offset{size_t(m_read_pos % uint64_t(vchBuf.size()))}; while (true) { - if (m_read_pos == nSrcPos) + if (m_read_pos == nSrcPos) { + // No more bytes available; read from the file into the buffer, + // setting nSrcPos to one beyond the end of the new data. + // Throws exception if end-of-file reached. Fill(); - if (vchBuf[m_read_pos % vchBuf.size()] == std::byte{ch}) { - break; } - m_read_pos++; + const size_t len{std::min<size_t>(vchBuf.size() - buf_offset, nSrcPos - m_read_pos)}; + const auto it_start{vchBuf.begin() + buf_offset}; + const auto it_find{std::find(it_start, it_start + len, byte)}; + const size_t inc{size_t(std::distance(it_start, it_find))}; + m_read_pos += inc; + if (inc < len) break; + buf_offset += inc; + if (buf_offset >= vchBuf.size()) buf_offset = 0; } } }; |