diff options
Diffstat (limited to 'src/core/BufferedCharReader.cpp')
-rw-r--r-- | src/core/BufferedCharReader.cpp | 144 |
1 files changed, 85 insertions, 59 deletions
diff --git a/src/core/BufferedCharReader.cpp b/src/core/BufferedCharReader.cpp index 15aa6c0..cf481df 100644 --- a/src/core/BufferedCharReader.cpp +++ b/src/core/BufferedCharReader.cpp @@ -16,6 +16,8 @@ along with this program. If not, see <http://www.gnu.org/licenses/>. */ +#include <array> + #include "BufferedCharReader.hpp" namespace ousia { @@ -28,14 +30,18 @@ static const uint8_t LB_STATE_CR = 0x20; static const uint8_t LB_STATE_MASK_CNT = 0x0F; static const uint8_t LB_STATE_MASK_TYPE = 0xF0; -/******************************************************************************* - * Struct BufferedCharReader::ReadCursor - ******************************************************************************/ - -BufferedCharReader::ReadCursor::ReadCursor(const bool destructive) : - destructive(destructive) +/* Struct BufferedCharReader::ReadCursor */ + +BufferedCharReader::ReadCursor::ReadCursor(unsigned int line, + unsigned int column, + bool destructive) + : line(line), + column(column), + bufferElem(0), + bufferPos(0), + destructive(destructive), + lbState(LB_STATE_NONE) { - reset(); } void BufferedCharReader::ReadCursor::assign(const ReadCursor &cursor) @@ -47,51 +53,50 @@ void BufferedCharReader::ReadCursor::assign(const ReadCursor &cursor) this->lbState = cursor.lbState; } -void BufferedCharReader::ReadCursor::reset() +/* Class BufferedCharReader */ + +BufferedCharReader::BufferedCharReader(int line, int column) + : inputStream(nullptr), + readCursor(line, column, true), + peekCursor(line, column, false), + depleted(false) { - this->line = 1; - this->column = 1; - this->bufferElem = 0; - this->bufferPos = 0; - this->lbState = LB_STATE_NONE; } -/******************************************************************************* - * Class BufferedCharReader - ******************************************************************************/ - -BufferedCharReader::BufferedCharReader() : - readCursor(true), peekCursor(false) +BufferedCharReader::BufferedCharReader(const std::string &str, int line, + int column) + : inputStream(nullptr), + readCursor(line, column, true), + peekCursor(line, column, false), + depleted(true) { - reset(); + buffer.push_back(str); } -void BufferedCharReader::reset() +BufferedCharReader::BufferedCharReader(std::istream &inputStream, int line, + int column) + : inputStream(&inputStream), + readCursor(line, column, true), + peekCursor(line, column, false), + depleted(false) { - readCursor.reset(); - peekCursor.reset(); - buffer.clear(); - closed = false; } -bool BufferedCharReader::feed(const std::string &data) +void BufferedCharReader::feed(const std::string &data) { - // Abort if the BufferedCharReader was closed - if (closed) { - return false; + if (!depleted && !inputStream) { + buffer.push_back(data); } - - // Append the data onto the queue - buffer.push_back(data); - return true; } void BufferedCharReader::close() { - closed = true; + if (!inputStream) { + depleted = true; + } } -bool BufferedCharReader::substituteLinebreaks(ReadCursor *cursor, char *c) +bool BufferedCharReader::substituteLinebreaks(ReadCursor &cursor, char *c) { // Handle line breaks, inserts breakes after the following character // combinations: \n, \r, \n\r, \r\n TODO: Change behaviour to \n, \n\r, \r\n @@ -100,11 +105,11 @@ bool BufferedCharReader::substituteLinebreaks(ReadCursor *cursor, char *c) const uint8_t type = (*c == '\n') ? LB_STATE_LF : LB_STATE_CR; // Read the last count and the last type from the state - const uint8_t lastCount = cursor->lbState & LB_STATE_MASK_CNT; - const uint8_t lastType = cursor->lbState & LB_STATE_MASK_TYPE; + const uint8_t lastCount = cursor.lbState & LB_STATE_MASK_CNT; + const uint8_t lastType = cursor.lbState & LB_STATE_MASK_TYPE; // Set the current linebreak type and counter in the state - cursor->lbState = ((lastCount + 1) & 1) | type; + cursor.lbState = ((lastCount + 1) & 1) | type; // If either this is the first instance of this character or the same // return character is repeated @@ -116,40 +121,61 @@ bool BufferedCharReader::substituteLinebreaks(ReadCursor *cursor, char *c) } // Find the state - cursor->lbState = LB_STATE_NONE; + cursor.lbState = LB_STATE_NONE; return true; } -bool BufferedCharReader::readCharacterAtCursor(ReadCursor *cursor, - char *c) +bool BufferedCharReader::readCharacterAtCursor(ReadCursor &cursor, char *c) { bool hasChar = false; while (!hasChar) { // Abort if the current buffer element does not point to a valid entry - // in the buffer -- we must wait until another data block has been fed - // into the buffer - if (cursor->bufferElem >= buffer.size()) { - return false; + // in the buffer -- we must try to feed another data block into the + // internal buffer + if (cursor.bufferElem >= buffer.size()) { + // Abort if there is no more data or no input stream is set + if (depleted || !inputStream) { + return false; + } + + // Read a buffer of the specified size + constexpr std::streamsize BUFFER_SIZE = 1024; + std::array<char, BUFFER_SIZE> buf; + const std::streamsize cnt = + (*inputStream).read(buf.data(), BUFFER_SIZE).gcount(); + + // If data has been read, append it to the input buffer and try + // again + if (cnt > 0) { + buffer.emplace_back(buf.data()); + continue; + } + + // End of file handling + if (inputStream->fail() || inputStream->eof()) { + depleted = true; + return false; + } } // Fetch the current element the peek pointer points to - const std::string &data = buffer[cursor->bufferElem]; + const std::string &data = buffer[cursor.bufferElem]; // Handle the "no data" case -- either in a destructive or // non-destructive manner. - if (cursor->bufferPos >= data.length()) { - if (cursor->destructive) { + if (cursor.bufferPos >= data.length()) { + if (cursor.destructive) { buffer.pop_front(); } else { - cursor->bufferElem++; + cursor.bufferElem++; } - cursor->bufferPos = 0; + cursor.bufferPos = 0; continue; } // Read the character, advance the buffer position - *c = *(data.data() + cursor->bufferPos); - cursor->bufferPos++; + *c = *(data.data() + cursor.bufferPos); + cursor.bufferPos++; // Substitute linebreaks with a single LF (0x0A) hasChar = substituteLinebreaks(cursor, c); @@ -157,12 +183,12 @@ bool BufferedCharReader::readCharacterAtCursor(ReadCursor *cursor, // Update the position counter if (*c == '\n') { - cursor->line++; - cursor->column = 1; + cursor.line++; + cursor.column = 1; } else { // Ignore UTF-8 continuation bytes if (!((*c & 0x80) && !(*c & 0x40))) { - cursor->column++; + cursor.column++; } } @@ -171,13 +197,13 @@ bool BufferedCharReader::readCharacterAtCursor(ReadCursor *cursor, bool BufferedCharReader::peek(char *c) { - return readCharacterAtCursor(&peekCursor, c); + return readCharacterAtCursor(peekCursor, c); } bool BufferedCharReader::read(char *c) { resetPeek(); - return readCharacterAtCursor(&readCursor, c); + return readCharacterAtCursor(readCursor, c); } void BufferedCharReader::consumePeek() @@ -200,7 +226,7 @@ void BufferedCharReader::resetPeek() bool BufferedCharReader::atEnd() { - if (closed) { + if (depleted || !inputStream) { if (buffer.size() <= 0) { return true; } else if (buffer.size() == 1) { @@ -209,5 +235,5 @@ bool BufferedCharReader::atEnd() } return false; } - } + |