lines.c

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/*  *************************************************************************************
    Copyright (c) 2021, Lowell D. Thomas
    All rights reserved.
    
    This file is part of APG Version 7.0.
    APG Version 7.0 may be used under the terms of the BSD 2-Clause License.
    
    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions are met:
    
    1. Redistributions of source code must retain the above copyright notice, this
       list of conditions and the following disclaimer.
    
    2. Redistributions in binary form must reproduce the above copyright notice,
       this list of conditions and the following disclaimer in the documentation
       and/or other materials provided with the distribution.
    
    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
    AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
    IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
    DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
    FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
    DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
    SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
    OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
    OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
    
*   *************************************************************************************/
#include "../library/lib.h"
#include "./lines.h"
 
#define LF 10
#define CR 13
 
static const void* s_vpMagicNumber = (void*)"lines";
 
typedef struct{
    const void* vpValidate; 
    exception* spException; 
    void* vpMem; 
    char* cpInput; 
    aint uiLength; 
    void* vpVecLines; 
    line* spLines; 
    aint uiLineCount; 
    aint uiIterator; 
} lines;
 
static void vInputLines(lines* spCtx);
static abool bFindLine(line* spLines, aint uiLineCount, aint uiCharIndex, aint* uipLine);
 
void* vpLinesCtor(exception* spEx, const char* cpInput, aint uiLength){
    if(bExValidate(spEx)){
        if(!cpInput || !uiLength){
            XTHROW(spEx, "input is NULL or empty");
        }
        // get the context
        void* vpMem = vpMemCtor(spEx);
        lines* spCtx = (lines*)vpMemAlloc(vpMem, sizeof(lines));
        memset((void*)spCtx, 0, sizeof(lines));
 
        // keep a local copy of the characters
        spCtx->cpInput = (char*)vpMemAlloc(vpMem, ((sizeof(char) * uiLength)));
        memcpy((void*)spCtx->cpInput, (void*)cpInput, (sizeof(char) * uiLength));
        spCtx->uiLength = uiLength;
 
        // set up the context
        spCtx->vpMem = vpMem;
        spCtx->spException = spEx;
        spCtx->vpVecLines = vpVecCtor(vpMem, sizeof(line), 512);
 
        // compute lines
        vInputLines(spCtx);
        spCtx->vpValidate = s_vpMagicNumber;
        return (void*)spCtx;
    }else{
        vExContext();
    }
    return NULL;
}
 
void vLinesDtor(void* vpCtx){
    lines* spCtx = (lines*)vpCtx;
    if(vpCtx){
        if(spCtx->vpValidate == s_vpMagicNumber){
            void* vpMem = spCtx->vpMem;
            memset(vpCtx, 0, sizeof(lines));
            vMemDtor(vpMem);
        }else{
            vExContext();
        }
    }
}
 
abool bLinesFindLine(void* vpCtx, aint uiOffset, aint* uipLine, aint* uipRelOffset){
    abool bReturn = APG_FAILURE;
    lines* spCtx = (lines*)vpCtx;
    if(vpCtx && (spCtx->vpValidate == s_vpMagicNumber)){
        if(!uipLine || !uipRelOffset){
            XTHROW(spCtx->spException, "line and relative offset pointers cannot be NULL");
        }
        if(bFindLine(spCtx->spLines, spCtx->uiLineCount, uiOffset, uipLine)){
            *uipRelOffset = uiOffset - spCtx->spLines[*uipLine].uiCharIndex;
            bReturn = APG_SUCCESS;
        }
    }else{
        vExContext();
    }
    return bReturn;
}
 
line* spLinesFirst(void* vpCtx){
    lines* spCtx = (lines*)vpCtx;
    if(vpCtx && (spCtx->vpValidate == s_vpMagicNumber)){
        spCtx->uiIterator = 1;
        return spCtx->spLines;
    }
    vExContext();
    return NULL;
}
line* spLinesNext(void* vpCtx){
    lines* spCtx = (lines*)vpCtx;
    if(vpCtx && (spCtx->vpValidate == s_vpMagicNumber)){
        if(spCtx->uiIterator < spCtx->uiLineCount){
            return &spCtx->spLines[spCtx->uiIterator++];
        }
        return NULL;
    }
    vExContext();
    return NULL;
}
 
aint uiLinesCount(void* vpCtx){
    lines* spCtx = (lines*)vpCtx;
    if(vpCtx && (spCtx->vpValidate == s_vpMagicNumber)){
        return spCtx->uiLineCount;
    }
    vExContext();
    return 0;
}
 
aint uiLinesLength(void* vpCtx){
    lines* spCtx = (lines*)vpCtx;
    if(vpCtx && (spCtx->vpValidate == s_vpMagicNumber)){
        return spCtx->uiLength;
    }
    vExContext();
    return 0;
}
 
static abool bFindLine(line* spLines, aint uiLineCount, aint uiCharIndex, aint* uipLine) {
    abool bReturn = APG_FAILURE;
    if (!spLines || !uiLineCount) {
        goto fail;
    }
    aint ui;
    line* spThis;
    if (uiLineCount < 5) {
        // linear search
        for (ui = 0; ui < uiLineCount; ui += 1) {
            spThis = &spLines[ui];
            if ((uiCharIndex >= spThis->uiCharIndex) && (uiCharIndex < (spThis->uiCharIndex + spThis->uiLineLength))) {
                *uipLine = ui;
                goto success;
            }
        }
        goto fail;
    } else {
        // binary search (https://en.wikipedia.org/wiki/Binary_search_algorithm)
        aint uiL = 0;
        aint uiR = uiLineCount - 1;
        aint uiM;
        while (uiL < uiR) {
            uiM = uiL + (uiR - uiL) / 2;
            spThis = &spLines[uiM];
            if (uiCharIndex >= (spThis->uiCharIndex + spThis->uiLineLength)) {
                uiL = uiM + 1;
                continue;
            }
            if (uiCharIndex < spThis->uiCharIndex) {
                uiR = uiM - 1;
                continue;
            }
            *uipLine = uiM;
            goto success;
        }
        if (uiL == uiR) {
            spThis = &spLines[uiL];
            if ((uiCharIndex >= spThis->uiCharIndex) && (uiCharIndex < (spThis->uiCharIndex + spThis->uiLineLength))) {
                *uipLine = uiL;
                goto success;
            }
        }
        goto fail;
    }
    success: bReturn = APG_SUCCESS;
    fail: ;
    return bReturn;
}
 
static void vInputLines(lines* spCtx) {
    aint uiLineIndex = 0;
    aint uiCharIndex = 0;
    aint uiTextLength = 0;
    char cChar;
    line sLine;
    void* vpVec = spCtx->vpVecLines;
    const char* cpInput = spCtx->cpInput;
    aint uiLen = spCtx->uiLength;
    vVecClear(vpVec);
    while (uiCharIndex < uiLen) {
        cChar = cpInput[uiCharIndex];
        if (cChar == LF) {
            // LF line ending
            sLine.uiLineIndex = uiLineIndex;
            sLine.uiCharIndex = uiCharIndex - uiTextLength;
            sLine.uiTextLength = uiTextLength;
            sLine.uiLineLength = uiTextLength + 1;
            uiCharIndex += 1;
            sLine.caLineEnd[0] = LF;
            sLine.caLineEnd[1] = 0;
            sLine.caLineEnd[2] = 0;
            vpVecPush(vpVec, (void*) &sLine);
            uiLineIndex += 1;
            uiTextLength = 0;
        } else if (cChar == CR) {
            sLine.uiLineIndex = uiLineIndex;
            sLine.uiCharIndex = uiCharIndex - uiTextLength;
            sLine.uiTextLength = uiTextLength;
            if ((uiCharIndex < (uiLen - 1)) && (cpInput[uiCharIndex + 1] == LF)) {
                // CRLF line ending
                sLine.uiLineLength = uiTextLength + 2;
                sLine.caLineEnd[0] = CR;
                sLine.caLineEnd[1] = LF;
                sLine.caLineEnd[2] = 0;
                uiCharIndex += 2;
            } else {
                // CR line ending
                sLine.uiLineLength = uiTextLength + 1;
                sLine.caLineEnd[0] = CR;
                sLine.caLineEnd[1] = 0;
                sLine.caLineEnd[2] = 0;
                uiCharIndex += 1;
            }
            vpVecPush(vpVec, (void*) &sLine);
            uiLineIndex += 1;
            uiTextLength = 0;
        } else {
            uiTextLength += 1;
            uiCharIndex += 1;
        }
    }
    if (uiTextLength > 0) {
        // last line had no line ending
        sLine.uiLineIndex = uiLineIndex;
        sLine.uiCharIndex = uiCharIndex - uiTextLength;
        sLine.uiTextLength = uiTextLength;
        sLine.uiLineLength = uiTextLength;
        sLine.caLineEnd[0] = 0;
        sLine.caLineEnd[1] = 0;
        sLine.caLineEnd[2] = 0;
        vpVecPush(vpVec, (void*) &sLine);
    }
    spCtx->spLines = (line*) vpVecFirst(spCtx->vpVecLines);
    spCtx->uiLineCount = uiVecLen(spCtx->vpVecLines);
}