From 3f62168ed0b088eec3cb2903f03966f7d501f564 Mon Sep 17 00:00:00 2001 From: Andreas Stöckel Date: Thu, 11 Dec 2014 15:26:50 +0100 Subject: moved to CharReader everywhere --- src/core/utils/CharReader.cpp | 643 ------------------------------------------ 1 file changed, 643 deletions(-) delete mode 100644 src/core/utils/CharReader.cpp (limited to 'src/core/utils/CharReader.cpp') diff --git a/src/core/utils/CharReader.cpp b/src/core/utils/CharReader.cpp deleted file mode 100644 index 61616d7..0000000 --- a/src/core/utils/CharReader.cpp +++ /dev/null @@ -1,643 +0,0 @@ -/* - Ousía - Copyright (C) 2014 Benjamin Paaßen, Andreas Stöckel - - This program is free software: you can redistribute it and/or modify - it under the terms of the GNU General Public License as published by - the Free Software Foundation, either version 3 of the License, or - (at your option) any later version. - - This program is distributed in the hope that it will be useful, - but WITHOUT ANY WARRANTY; without even the implied warranty of - MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - GNU General Public License for more details. - - You should have received a copy of the GNU General Public License - along with this program. If not, see . -*/ - -#include -#include -#include -#include - -#include - -#include "CharReader.hpp" - -namespace ousia { -namespace utils { - -/* Helper functions */ - -/** - * istreamReadCallback is used internally by the Buffer calss to stream data - * from an input stream. - * - * @param buf is points a the target memory region. - * @param size is the requested number of bytes. - * @param userData is a pointer at some user defined data. - * @return the actual number of bytes read. If the result is smaller than - * the requested size, this tells the Buffer that the end of the input - * stream is reached. - */ -static size_t istreamReadCallback(char *buf, size_t size, void *userData) -{ - return (static_cast(userData))->read(buf, size).gcount(); -} - -/* Class Buffer */ - -Buffer::Buffer(ReadCallback callback, void *userData) - : callback(callback), - userData(userData), - reachedEnd(false), - startBucket(buckets.end()), - endBucket(buckets.end()), - startOffset(0), - firstDead(0) -{ - // Load a first block of data from the stream - stream(); - startBucket = buckets.begin(); -} - -Buffer::Buffer(std::istream &istream) : Buffer(istreamReadCallback, &istream) {} - -Buffer::Buffer(const std::string &str) - : callback(nullptr), - userData(nullptr), - reachedEnd(true), - startBucket(buckets.end()), - endBucket(buckets.end()), - startOffset(0), - firstDead(0) -{ - // Copy the given string into a first buffer and set the start buffer - // correctly - Bucket &bucket = nextBucket(); - bucket.resize(str.size()); - std::copy(str.begin(), str.end(), bucket.begin()); - startBucket = buckets.begin(); -} - -#ifndef NDEBUG -Buffer::~Buffer() -{ - // Make sure all cursors have been deleted - for (bool cursor_alive: alive) { - assert(!cursor_alive); - } -} -#endif - -void Buffer::advance(BucketIterator &it) -{ - it++; - if (it == buckets.end()) { - it = buckets.begin(); - } -} - -void Buffer::advance(BucketList::const_iterator &it) const -{ - it++; - if (it == buckets.cend()) { - it = buckets.cbegin(); - } -} - -Buffer::Bucket &Buffer::nextBucket() -{ - constexpr size_t MAXVAL = std::numeric_limits::max(); - - // Fetch the minimum bucket index - size_t minBucketIdx = MAXVAL; - for (size_t i = 0; i < cursors.size(); i++) { - if (alive[i]) { - // Fetch references to the bucket and the cursor - const Cursor &cur = cursors[i]; - const Bucket &bucket = *(cur.bucket); - - // Increment the bucket index by one, if the cursor is at the end - // of the bucket (only valid if the LOOKBACK_SIZE is set to zero) - size_t bIdx = cur.bucketIdx; - if (LOOKBACK_SIZE == 0 && cur.bucketOffs == bucket.size()) { - bIdx++; - } - - // Decrement the bucket index by one, if the previous bucket still - // needs to be reached and cannot be overridden - if (bIdx > 0 && cur.bucketOffs < LOOKBACK_SIZE) { - bIdx--; - } - - // Set the bucket index to the minium - minBucketIdx = std::min(minBucketIdx, bIdx); - } - } - - // If there is space between the current start bucket and the read - // cursor, the start bucket can be safely overridden. - if (minBucketIdx > 0 && minBucketIdx != MAXVAL) { - // All cursor bucket indices will be decreased by one - for (size_t i = 0; i < cursors.size(); i++) { - cursors[i].bucketIdx--; - } - - // Increment the start offset - startOffset += startBucket->size(); - - // The old start bucket is the new end bucket - endBucket = startBucket; - - // Advance the start bucket, wrap around at the end of the list - advance(startBucket); - } else { - // No free bucket, insert a new one before the start bucket - endBucket = buckets.emplace(startBucket); - } - return *endBucket; -} - -Buffer::CursorId Buffer::nextCursor() -{ - bool hasCursor = false; - CursorId res = 0; - - // Search for the next free cursor starting with minNextCursorId - for (size_t i = firstDead; i < alive.size(); i++) { - if (!alive[i]) { - res = i; - hasCursor = true; - break; - } - } - - // Add a new cursor to the cursor list if no cursor is currently free - if (!hasCursor) { - res = cursors.size(); - cursors.resize(res + 1); - alive.resize(res + 1); - } - - // The next dead cursor is at least the next cursor - firstDead = res + 1; - - // Mark the new cursor as alive - alive[res] = true; - - return res; -} - -void Buffer::stream() -{ - // Fetch the bucket into which the data should be inserted, make sure it - // has the correct size - Bucket &tar = nextBucket(); - tar.resize(REQUEST_SIZE); - - // Read data from the stream into the target buffer - size_t size = callback(tar.data(), REQUEST_SIZE, userData); - - // If not enough bytes were returned, we're at the end of the stream - if (size < REQUEST_SIZE) { - tar.resize(size); - reachedEnd = true; - } -} - -Buffer::CursorId Buffer::createCursor() -{ - CursorId res = nextCursor(); - cursors[res].bucket = startBucket; - cursors[res].bucketIdx = 0; - cursors[res].bucketOffs = 0; - return res; -} - -Buffer::CursorId Buffer::createCursor(Buffer::CursorId ref) -{ - CursorId res = nextCursor(); - cursors[res] = cursors[ref]; - return res; -} - -void Buffer::copyCursor(Buffer::CursorId from, Buffer::CursorId to) -{ - cursors[to] = cursors[from]; -} - -void Buffer::deleteCursor(Buffer::CursorId cursor) -{ - alive[cursor] = false; - firstDead = std::min(firstDead, cursor); -} - -size_t Buffer::offset(Buffer::CursorId cursor) const -{ - const Cursor &cur = cursors[cursor]; - size_t offs = startOffset + cur.bucketOffs; - BucketList::const_iterator it = startBucket; - while (it != cur.bucket) { - offs += it->size(); - advance(it); - } - return offs; -} - -size_t Buffer::moveForward(CursorId cursor, size_t relativeOffs) -{ - size_t offs = relativeOffs; - Cursor &cur = cursors[cursor]; - while (offs > 0) { - // Fetch the current bucket of the cursor - Bucket &bucket = *(cur.bucket); - - // If there is enough space in the bucket, simply increment the bucket - // offset by the given relative offset - const size_t space = bucket.size() - cur.bucketOffs; - if (space >= offs) { - cur.bucketOffs += offs; - break; - } else { - // Go to the end of the current bucket otherwise - offs -= space; - cur.bucketOffs = bucket.size(); - - // Go to the next bucket - if (cur.bucket != endBucket) { - // Go to the next bucket - advance(cur.bucket); - cur.bucketIdx++; - cur.bucketOffs = 0; - } else { - // Abort, if there is no more data to stream, otherwise just - // load new data - if (reachedEnd) { - return relativeOffs - offs; - } - stream(); - } - } - } - return relativeOffs; -} - -size_t Buffer::moveBackward(CursorId cursor, size_t relativeOffs) -{ - size_t offs = relativeOffs; - Cursor &cur = cursors[cursor]; - while (offs > 0) { - // If there is enough space in the bucket, simply decrement the bucket - // offset by the given relative offset - if (cur.bucketOffs >= offs) { - cur.bucketOffs -= offs; - break; - } else { - // Go to the beginning of the current bucket otherwise - offs -= cur.bucketOffs; - cur.bucketOffs = 0; - - // Abort if there is no more bucket to got back to - if (cur.bucketIdx == 0) { - return relativeOffs - offs; - } - - // Go to the previous bucket (wrap around at the beginning of the - // list) - if (cur.bucket == buckets.begin()) { - cur.bucket = buckets.end(); - } - cur.bucket--; - - // Decrement the bucket index, and set the current offset to the - // end of the new bucket - cur.bucketIdx--; - cur.bucketOffs = cur.bucket->size(); - } - } - return relativeOffs; -} - -ssize_t Buffer::moveCursor(CursorId cursor, ssize_t relativeOffs) -{ - if (relativeOffs > 0) { - return moveForward(cursor, relativeOffs); - } else if (relativeOffs < 0) { - return -moveBackward(cursor, -relativeOffs); - } else { - return 0; - } -} - -bool Buffer::atEnd(Buffer::CursorId cursor) const -{ - const Cursor &c = cursors[cursor]; - return reachedEnd && - (c.bucket == endBucket && c.bucketOffs == endBucket->size()); -} - -bool Buffer::fetchCharacter(CursorId cursor, char &c, bool incr) -{ - Cursor &cur = cursors[cursor]; - while (true) { - // Reference at the current bucket - Bucket &bucket = *(cur.bucket); - - // If there is still data in the current bucket, return this data - if (cur.bucketOffs < bucket.size()) { - c = bucket[cur.bucketOffs]; - if (incr) { - cur.bucketOffs++; - } - return true; - } else if (cur.bucket == endBucket) { - // Return false if the end of the stream has been reached, otherwise - // load new data - if (reachedEnd) { - return false; - } - stream(); - } - - // Go to the next bucket - cur.bucketIdx++; - cur.bucketOffs = 0; - advance(cur.bucket); - } -} - -bool Buffer::read(Buffer::CursorId cursor, char &c) -{ - return fetchCharacter(cursor, c, true); -} - -bool Buffer::fetch(CursorId cursor, char &c) -{ - return fetchCharacter(cursor, c, false); -} - -/* CharReader::Cursor class */ - -void CharReader::Cursor::assign(std::shared_ptr buffer, - CharReader::Cursor &cursor) -{ - // Copy the cursor position - buffer->copyCursor(cursor.cursor, this->cursor); - - // Copy the state - line = cursor.line; - column = cursor.column; -} - -/* CharReader class */ - -CharReader::CharReader(std::shared_ptr buffer, size_t line, - size_t column) - : buffer(buffer), - readCursor(buffer->createCursor(), line, column), - peekCursor(buffer->createCursor(), line, column), - coherent(true) -{ -} - -CharReader::CharReader(const std::string &str, size_t line, size_t column) - : CharReader(std::shared_ptr{new Buffer{str}}, line, column) -{ -} - -CharReader::CharReader(std::istream &istream, size_t line, size_t column) - : CharReader(std::shared_ptr{new Buffer{istream}}, line, column) -{ -} - -CharReader::~CharReader() -{ - buffer->deleteCursor(readCursor.cursor); - buffer->deleteCursor(peekCursor.cursor); -} - -bool CharReader::readAtCursor(Cursor &cursor, char &c) -{ - // Return false if we're at the end of the stream - if (!buffer->read(cursor.cursor, c)) { - return false; - } - - // Substitute linebreak sequences with a single '\n' - if (c == '\n' || c == '\r') { - // Output a single \n - c = '\n'; - - // Check whether the next character is a continuation of the - // current character - char c2; - if (buffer->read(cursor.cursor, c2)) { - if ((c2 != '\n' && c2 != '\r') || c2 == c) { - buffer->moveCursor(cursor.cursor, -1); - } - } - } - - // Count lines and columns - if (c == '\n') { - // A linebreak was reached, go to the next line - cursor.line++; - cursor.column = 1; - } else { - // Ignore UTF-8 continuation bytes - if (!((c & 0x80) && !(c & 0x40))) { - cursor.column++; - } - } - return true; -} - -bool CharReader::peek(char &c) -{ - // If the reader was coherent, update the peek cursor state - if (coherent) { - peekCursor.assign(buffer, readCursor); - coherent = false; - } - - // Read a character from the peek cursor - return readAtCursor(peekCursor, c); -} - -bool CharReader::read(char &c) -{ - // Read a character from the buffer at the current read cursor - bool res = readAtCursor(readCursor, c); - - // Set the peek position to the current read position, if reading was not - // coherent - if (!coherent) { - peekCursor.assign(buffer, readCursor); - coherent = true; - } else { - buffer->copyCursor(readCursor.cursor, peekCursor.cursor); - } - - // Return the result of the read function - return res; -} - -void CharReader::resetPeek() -{ - if (!coherent) { - peekCursor.assign(buffer, readCursor); - coherent = true; - } -} - -void CharReader::consumePeek() -{ - if (!coherent) { - readCursor.assign(buffer, peekCursor); - coherent = true; - } -} - -bool CharReader::consumeWhitespace() -{ - char c; - while (peek(c)) { - if (!Utils::isWhitespace(c)) { - resetPeek(); - return true; - } - consumePeek(); - } - return false; -} - -CharReaderFork CharReader::fork() -{ - return CharReaderFork(buffer, readCursor, peekCursor, coherent); -} - -CharReader::Context CharReader::getContext(ssize_t maxSize) -{ - // Clone the current read cursor - Buffer::CursorId cur = buffer->createCursor(readCursor.cursor); - - // Fetch the start position of the search - ssize_t offs = buffer->offset(cur); - ssize_t start = offs; - ssize_t end = offs; - char c; - - // Search the beginning of the line with the last non-whitespace character - bool hadNonWhitespace = false; - bool foundBegin = false; - for (ssize_t i = 0; i < maxSize; i++) { - // Fetch the character at the current position - if (buffer->fetch(cur, c)) { - // Abort, at linebreaks if we found a non-linebreak character - hadNonWhitespace = hadNonWhitespace || !Utils::isWhitespace(c); - if (hadNonWhitespace && (c == '\n' || c == '\r')) { - buffer->moveCursor(cur, 1); - start++; - foundBegin = true; - break; - } - } - if (buffer->moveCursor(cur, -1) == 0) { - foundBegin = true; - break; - } else { - // Update the start position and the hadNonWhitespace flag - start--; - } - } - - // Search the end of the line - buffer->moveCursor(cur, offs - start); - bool foundEnd = false; - for (ssize_t i = 0; i < maxSize; i++) { - // Increment the end counter if a character was read, abort if the end - // of the stream has been reached - if (buffer->read(cur, c)) { - end++; - } else { - foundEnd = true; - break; - } - - // Abort on linebreak characters - if (c == '\n' || c == '\r') { - foundEnd = true; - break; - } - } - - // Calculate the truncated start and end position and limit the number of - // characters to the maximum number of characters - ssize_t tStart = start; - ssize_t tEnd = end; - if (tEnd - tStart > maxSize) { - tStart = std::max(offs - maxSize / 2, tStart); - tEnd = tStart + maxSize; - } - - // Try to go to the calculated start position and fetch the actual start - // position - ssize_t aStart = end + buffer->moveCursor(cur, tStart - end); - if (aStart > tStart) { - tEnd = tEnd + (aStart - tStart); - tStart = aStart; - } - - // Read one line - std::stringstream ss; - size_t relPos = 0; - for (ssize_t i = tStart; i < tEnd; i++) { - if (buffer->read(cur, c)) { - // Break once a linebreak is reached - if (c == '\n' || c == '\r') { - break; - } - - // Add the current character to the output - ss << c; - - // Increment the string-relative offset as long as the original - // offset is not reached in the for loop - if (i < offs) { - relPos++; - } - } - } - - // Delete the newly created cursor - buffer->deleteCursor(cur); - - return CharReader::Context{ss.str(), relPos, !foundBegin || tStart != start, - !foundEnd || tEnd != end}; -} - -/* Class CharReaderFork */ - -CharReaderFork::CharReaderFork(std::shared_ptr buffer, - CharReader::Cursor &parentReadCursor, - CharReader::Cursor &parentPeekCursor, - bool coherent) - : CharReader(buffer, 1, 1), - parentReadCursor(parentReadCursor), - parentPeekCursor(parentPeekCursor) -{ - readCursor.assign(buffer, parentReadCursor); - peekCursor.assign(buffer, parentPeekCursor); - this->coherent = coherent; -} - -void CharReaderFork::commit() -{ - parentReadCursor.assign(buffer, readCursor); - parentPeekCursor.assign(buffer, peekCursor); -} -} -} - -- cgit v1.2.3