pdfjs-dist/lib/core/operator_list.js

/**
 * @licstart The following is the entire license notice for the
 * Javascript code in this page
 *
 * Copyright 2021 Mozilla Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * @licend The above is the entire license notice for the
 * Javascript code in this page
 */
"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.OperatorList = void 0;

var _util = require("../shared/util.js");

function addState(parentState, pattern, checkFn, iterateFn, processFn) {
  let state = parentState;

  for (let i = 0, ii = pattern.length - 1; i < ii; i++) {
    const item = pattern[i];
    state = state[item] || (state[item] = []);
  }

  state[pattern[pattern.length - 1]] = {
    checkFn,
    iterateFn,
    processFn
  };
}

function handlePaintSolidColorImageMask(iFirstSave, count, fnArray, argsArray) {
  const iFirstPIMXO = iFirstSave + 2;
  let i;

  for (i = 0; i < count; i++) {
    const arg = argsArray[iFirstPIMXO + 4 * i];
    const imageMask = arg.length === 1 && arg[0];

    if (imageMask && imageMask.width === 1 && imageMask.height === 1 && (!imageMask.data.length || imageMask.data.length === 1 && imageMask.data[0] === 0)) {
      fnArray[iFirstPIMXO + 4 * i] = _util.OPS.paintSolidColorImageMask;
      continue;
    }

    break;
  }

  return count - i;
}

const InitialState = [];
addState(InitialState, [_util.OPS.save, _util.OPS.transform, _util.OPS.paintInlineImageXObject, _util.OPS.restore], null, function iterateInlineImageGroup(context, i) {
  const fnArray = context.fnArray;
  const iFirstSave = context.iCurr - 3;
  const pos = (i - iFirstSave) % 4;

  switch (pos) {
    case 0:
      return fnArray[i] === _util.OPS.save;

    case 1:
      return fnArray[i] === _util.OPS.transform;

    case 2:
      return fnArray[i] === _util.OPS.paintInlineImageXObject;

    case 3:
      return fnArray[i] === _util.OPS.restore;
  }

  throw new Error(`iterateInlineImageGroup - invalid pos: ${pos}`);
}, function foundInlineImageGroup(context, i) {
  const MIN_IMAGES_IN_INLINE_IMAGES_BLOCK = 10;
  const MAX_IMAGES_IN_INLINE_IMAGES_BLOCK = 200;
  const MAX_WIDTH = 1000;
  const IMAGE_PADDING = 1;
  const fnArray = context.fnArray,
        argsArray = context.argsArray;
  const curr = context.iCurr;
  const iFirstSave = curr - 3;
  const iFirstTransform = curr - 2;
  const iFirstPIIXO = curr - 1;
  const count = Math.min(Math.floor((i - iFirstSave) / 4), MAX_IMAGES_IN_INLINE_IMAGES_BLOCK);

  if (count < MIN_IMAGES_IN_INLINE_IMAGES_BLOCK) {
    return i - (i - iFirstSave) % 4;
  }

  let maxX = 0;
  const map = [];
  let maxLineHeight = 0;
  let currentX = IMAGE_PADDING,
      currentY = IMAGE_PADDING;

  for (let q = 0; q < count; q++) {
    const transform = argsArray[iFirstTransform + (q << 2)];
    const img = argsArray[iFirstPIIXO + (q << 2)][0];

    if (currentX + img.width > MAX_WIDTH) {
      maxX = Math.max(maxX, currentX);
      currentY += maxLineHeight + 2 * IMAGE_PADDING;
      currentX = 0;
      maxLineHeight = 0;
    }

    map.push({
      transform,
      x: currentX,
      y: currentY,
      w: img.width,
      h: img.height
    });
    currentX += img.width + 2 * IMAGE_PADDING;
    maxLineHeight = Math.max(maxLineHeight, img.height);
  }

  const imgWidth = Math.max(maxX, currentX) + IMAGE_PADDING;
  const imgHeight = currentY + maxLineHeight + IMAGE_PADDING;
  const imgData = new Uint8ClampedArray(imgWidth * imgHeight * 4);
  const imgRowSize = imgWidth << 2;

  for (let q = 0; q < count; q++) {
    const data = argsArray[iFirstPIIXO + (q << 2)][0].data;
    const rowSize = map[q].w << 2;
    let dataOffset = 0;
    let offset = map[q].x + map[q].y * imgWidth << 2;
    imgData.set(data.subarray(0, rowSize), offset - imgRowSize);

    for (let k = 0, kk = map[q].h; k < kk; k++) {
      imgData.set(data.subarray(dataOffset, dataOffset + rowSize), offset);
      dataOffset += rowSize;
      offset += imgRowSize;
    }

    imgData.set(data.subarray(dataOffset - rowSize, dataOffset), offset);

    while (offset >= 0) {
      data[offset - 4] = data[offset];
      data[offset - 3] = data[offset + 1];
      data[offset - 2] = data[offset + 2];
      data[offset - 1] = data[offset + 3];
      data[offset + rowSize] = data[offset + rowSize - 4];
      data[offset + rowSize + 1] = data[offset + rowSize - 3];
      data[offset + rowSize + 2] = data[offset + rowSize - 2];
      data[offset + rowSize + 3] = data[offset + rowSize - 1];
      offset -= imgRowSize;
    }
  }

  fnArray.splice(iFirstSave, count * 4, _util.OPS.paintInlineImageXObjectGroup);
  argsArray.splice(iFirstSave, count * 4, [{
    width: imgWidth,
    height: imgHeight,
    kind: _util.ImageKind.RGBA_32BPP,
    data: imgData
  }, map]);
  return iFirstSave + 1;
});
addState(InitialState, [_util.OPS.save, _util.OPS.transform, _util.OPS.paintImageMaskXObject, _util.OPS.restore], null, function iterateImageMaskGroup(context, i) {
  const fnArray = context.fnArray;
  const iFirstSave = context.iCurr - 3;
  const pos = (i - iFirstSave) % 4;

  switch (pos) {
    case 0:
      return fnArray[i] === _util.OPS.save;

    case 1:
      return fnArray[i] === _util.OPS.transform;

    case 2:
      return fnArray[i] === _util.OPS.paintImageMaskXObject;

    case 3:
      return fnArray[i] === _util.OPS.restore;
  }

  throw new Error(`iterateImageMaskGroup - invalid pos: ${pos}`);
}, function foundImageMaskGroup(context, i) {
  const MIN_IMAGES_IN_MASKS_BLOCK = 10;
  const MAX_IMAGES_IN_MASKS_BLOCK = 100;
  const MAX_SAME_IMAGES_IN_MASKS_BLOCK = 1000;
  const fnArray = context.fnArray,
        argsArray = context.argsArray;
  const curr = context.iCurr;
  const iFirstSave = curr - 3;
  const iFirstTransform = curr - 2;
  const iFirstPIMXO = curr - 1;
  let count = Math.floor((i - iFirstSave) / 4);
  count = handlePaintSolidColorImageMask(iFirstSave, count, fnArray, argsArray);

  if (count < MIN_IMAGES_IN_MASKS_BLOCK) {
    return i - (i - iFirstSave) % 4;
  }

  let isSameImage = false;
  let iTransform, transformArgs;
  const firstPIMXOArg0 = argsArray[iFirstPIMXO][0];
  const firstTransformArg0 = argsArray[iFirstTransform][0],
        firstTransformArg1 = argsArray[iFirstTransform][1],
        firstTransformArg2 = argsArray[iFirstTransform][2],
        firstTransformArg3 = argsArray[iFirstTransform][3];

  if (firstTransformArg1 === firstTransformArg2) {
    isSameImage = true;
    iTransform = iFirstTransform + 4;
    let iPIMXO = iFirstPIMXO + 4;

    for (let q = 1; q < count; q++, iTransform += 4, iPIMXO += 4) {
      transformArgs = argsArray[iTransform];

      if (argsArray[iPIMXO][0] !== firstPIMXOArg0 || transformArgs[0] !== firstTransformArg0 || transformArgs[1] !== firstTransformArg1 || transformArgs[2] !== firstTransformArg2 || transformArgs[3] !== firstTransformArg3) {
        if (q < MIN_IMAGES_IN_MASKS_BLOCK) {
          isSameImage = false;
        } else {
          count = q;
        }

        break;
      }
    }
  }

  if (isSameImage) {
    count = Math.min(count, MAX_SAME_IMAGES_IN_MASKS_BLOCK);
    const positions = new Float32Array(count * 2);
    iTransform = iFirstTransform;

    for (let q = 0; q < count; q++, iTransform += 4) {
      transformArgs = argsArray[iTransform];
      positions[q << 1] = transformArgs[4];
      positions[(q << 1) + 1] = transformArgs[5];
    }

    fnArray.splice(iFirstSave, count * 4, _util.OPS.paintImageMaskXObjectRepeat);
    argsArray.splice(iFirstSave, count * 4, [firstPIMXOArg0, firstTransformArg0, firstTransformArg1, firstTransformArg2, firstTransformArg3, positions]);
  } else {
    count = Math.min(count, MAX_IMAGES_IN_MASKS_BLOCK);
    const images = [];

    for (let q = 0; q < count; q++) {
      transformArgs = argsArray[iFirstTransform + (q << 2)];
      const maskParams = argsArray[iFirstPIMXO + (q << 2)][0];
      images.push({
        data: maskParams.data,
        width: maskParams.width,
        height: maskParams.height,
        transform: transformArgs
      });
    }

    fnArray.splice(iFirstSave, count * 4, _util.OPS.paintImageMaskXObjectGroup);
    argsArray.splice(iFirstSave, count * 4, [images]);
  }

  return iFirstSave + 1;
});
addState(InitialState, [_util.OPS.save, _util.OPS.transform, _util.OPS.paintImageXObject, _util.OPS.restore], function (context) {
  const argsArray = context.argsArray;
  const iFirstTransform = context.iCurr - 2;
  return argsArray[iFirstTransform][1] === 0 && argsArray[iFirstTransform][2] === 0;
}, function iterateImageGroup(context, i) {
  const fnArray = context.fnArray,
        argsArray = context.argsArray;
  const iFirstSave = context.iCurr - 3;
  const pos = (i - iFirstSave) % 4;

  switch (pos) {
    case 0:
      return fnArray[i] === _util.OPS.save;

    case 1:
      if (fnArray[i] !== _util.OPS.transform) {
        return false;
      }

      const iFirstTransform = context.iCurr - 2;
      const firstTransformArg0 = argsArray[iFirstTransform][0];
      const firstTransformArg3 = argsArray[iFirstTransform][3];

      if (argsArray[i][0] !== firstTransformArg0 || argsArray[i][1] !== 0 || argsArray[i][2] !== 0 || argsArray[i][3] !== firstTransformArg3) {
        return false;
      }

      return true;

    case 2:
      if (fnArray[i] !== _util.OPS.paintImageXObject) {
        return false;
      }

      const iFirstPIXO = context.iCurr - 1;
      const firstPIXOArg0 = argsArray[iFirstPIXO][0];

      if (argsArray[i][0] !== firstPIXOArg0) {
        return false;
      }

      return true;

    case 3:
      return fnArray[i] === _util.OPS.restore;
  }

  throw new Error(`iterateImageGroup - invalid pos: ${pos}`);
}, function (context, i) {
  const MIN_IMAGES_IN_BLOCK = 3;
  const MAX_IMAGES_IN_BLOCK = 1000;
  const fnArray = context.fnArray,
        argsArray = context.argsArray;
  const curr = context.iCurr;
  const iFirstSave = curr - 3;
  const iFirstTransform = curr - 2;
  const iFirstPIXO = curr - 1;
  const firstPIXOArg0 = argsArray[iFirstPIXO][0];
  const firstTransformArg0 = argsArray[iFirstTransform][0];
  const firstTransformArg3 = argsArray[iFirstTransform][3];
  const count = Math.min(Math.floor((i - iFirstSave) / 4), MAX_IMAGES_IN_BLOCK);

  if (count < MIN_IMAGES_IN_BLOCK) {
    return i - (i - iFirstSave) % 4;
  }

  const positions = new Float32Array(count * 2);
  let iTransform = iFirstTransform;

  for (let q = 0; q < count; q++, iTransform += 4) {
    const transformArgs = argsArray[iTransform];
    positions[q << 1] = transformArgs[4];
    positions[(q << 1) + 1] = transformArgs[5];
  }

  const args = [firstPIXOArg0, firstTransformArg0, firstTransformArg3, positions];
  fnArray.splice(iFirstSave, count * 4, _util.OPS.paintImageXObjectRepeat);
  argsArray.splice(iFirstSave, count * 4, args);
  return iFirstSave + 1;
});
addState(InitialState, [_util.OPS.beginText, _util.OPS.setFont, _util.OPS.setTextMatrix, _util.OPS.showText, _util.OPS.endText], null, function iterateShowTextGroup(context, i) {
  const fnArray = context.fnArray,
        argsArray = context.argsArray;
  const iFirstSave = context.iCurr - 4;
  const pos = (i - iFirstSave) % 5;

  switch (pos) {
    case 0:
      return fnArray[i] === _util.OPS.beginText;

    case 1:
      return fnArray[i] === _util.OPS.setFont;

    case 2:
      return fnArray[i] === _util.OPS.setTextMatrix;

    case 3:
      if (fnArray[i] !== _util.OPS.showText) {
        return false;
      }

      const iFirstSetFont = context.iCurr - 3;
      const firstSetFontArg0 = argsArray[iFirstSetFont][0];
      const firstSetFontArg1 = argsArray[iFirstSetFont][1];

      if (argsArray[i][0] !== firstSetFontArg0 || argsArray[i][1] !== firstSetFontArg1) {
        return false;
      }

      return true;

    case 4:
      return fnArray[i] === _util.OPS.endText;
  }

  throw new Error(`iterateShowTextGroup - invalid pos: ${pos}`);
}, function (context, i) {
  const MIN_CHARS_IN_BLOCK = 3;
  const MAX_CHARS_IN_BLOCK = 1000;
  const fnArray = context.fnArray,
        argsArray = context.argsArray;
  const curr = context.iCurr;
  const iFirstBeginText = curr - 4;
  const iFirstSetFont = curr - 3;
  const iFirstSetTextMatrix = curr - 2;
  const iFirstShowText = curr - 1;
  const iFirstEndText = curr;
  const firstSetFontArg0 = argsArray[iFirstSetFont][0];
  const firstSetFontArg1 = argsArray[iFirstSetFont][1];
  let count = Math.min(Math.floor((i - iFirstBeginText) / 5), MAX_CHARS_IN_BLOCK);

  if (count < MIN_CHARS_IN_BLOCK) {
    return i - (i - iFirstBeginText) % 5;
  }

  let iFirst = iFirstBeginText;

  if (iFirstBeginText >= 4 && fnArray[iFirstBeginText - 4] === fnArray[iFirstSetFont] && fnArray[iFirstBeginText - 3] === fnArray[iFirstSetTextMatrix] && fnArray[iFirstBeginText - 2] === fnArray[iFirstShowText] && fnArray[iFirstBeginText - 1] === fnArray[iFirstEndText] && argsArray[iFirstBeginText - 4][0] === firstSetFontArg0 && argsArray[iFirstBeginText - 4][1] === firstSetFontArg1) {
    count++;
    iFirst -= 5;
  }

  let iEndText = iFirst + 4;

  for (let q = 1; q < count; q++) {
    fnArray.splice(iEndText, 3);
    argsArray.splice(iEndText, 3);
    iEndText += 2;
  }

  return iEndText + 1;
});

class NullOptimizer {
  constructor(queue) {
    this.queue = queue;
  }

  _optimize() {}

  push(fn, args) {
    this.queue.fnArray.push(fn);
    this.queue.argsArray.push(args);

    this._optimize();
  }

  flush() {}

  reset() {}

}

class QueueOptimizer extends NullOptimizer {
  constructor(queue) {
    super(queue);
    this.state = null;
    this.context = {
      iCurr: 0,
      fnArray: queue.fnArray,
      argsArray: queue.argsArray
    };
    this.match = null;
    this.lastProcessed = 0;
  }

  _optimize() {
    const fnArray = this.queue.fnArray;
    let i = this.lastProcessed,
        ii = fnArray.length;
    let state = this.state;
    let match = this.match;

    if (!state && !match && i + 1 === ii && !InitialState[fnArray[i]]) {
      this.lastProcessed = ii;
      return;
    }

    const context = this.context;

    while (i < ii) {
      if (match) {
        const iterate = (0, match.iterateFn)(context, i);

        if (iterate) {
          i++;
          continue;
        }

        i = (0, match.processFn)(context, i + 1);
        ii = fnArray.length;
        match = null;
        state = null;

        if (i >= ii) {
          break;
        }
      }

      state = (state || InitialState)[fnArray[i]];

      if (!state || Array.isArray(state)) {
        i++;
        continue;
      }

      context.iCurr = i;
      i++;

      if (state.checkFn && !(0, state.checkFn)(context)) {
        state = null;
        continue;
      }

      match = state;
      state = null;
    }

    this.state = state;
    this.match = match;
    this.lastProcessed = i;
  }

  flush() {
    while (this.match) {
      const length = this.queue.fnArray.length;
      this.lastProcessed = (0, this.match.processFn)(this.context, length);
      this.match = null;
      this.state = null;

      this._optimize();
    }
  }

  reset() {
    this.state = null;
    this.match = null;
    this.lastProcessed = 0;
  }

}

class OperatorList {
  static get CHUNK_SIZE() {
    return (0, _util.shadow)(this, "CHUNK_SIZE", 1000);
  }

  static get CHUNK_SIZE_ABOUT() {
    return (0, _util.shadow)(this, "CHUNK_SIZE_ABOUT", this.CHUNK_SIZE - 5);
  }

  constructor(intent, streamSink) {
    this._streamSink = streamSink;
    this.fnArray = [];
    this.argsArray = [];

    if (streamSink && !(intent && intent.startsWith("oplist-"))) {
      this.optimizer = new QueueOptimizer(this);
    } else {
      this.optimizer = new NullOptimizer(this);
    }

    this.dependencies = new Set();
    this._totalLength = 0;
    this.weight = 0;
    this._resolved = streamSink ? null : Promise.resolve();
  }

  get length() {
    return this.argsArray.length;
  }

  get ready() {
    return this._resolved || this._streamSink.ready;
  }

  get totalLength() {
    return this._totalLength + this.length;
  }

  addOp(fn, args) {
    this.optimizer.push(fn, args);
    this.weight++;

    if (this._streamSink) {
      if (this.weight >= OperatorList.CHUNK_SIZE) {
        this.flush();
      } else if (this.weight >= OperatorList.CHUNK_SIZE_ABOUT && (fn === _util.OPS.restore || fn === _util.OPS.endText)) {
        this.flush();
      }
    }
  }

  addDependency(dependency) {
    if (this.dependencies.has(dependency)) {
      return;
    }

    this.dependencies.add(dependency);
    this.addOp(_util.OPS.dependency, [dependency]);
  }

  addDependencies(dependencies) {
    for (const dependency of dependencies) {
      this.addDependency(dependency);
    }
  }

  addOpList(opList) {
    if (!(opList instanceof OperatorList)) {
      (0, _util.warn)('addOpList - ignoring invalid "opList" parameter.');
      return;
    }

    for (const dependency of opList.dependencies) {
      this.dependencies.add(dependency);
    }

    for (let i = 0, ii = opList.length; i < ii; i++) {
      this.addOp(opList.fnArray[i], opList.argsArray[i]);
    }
  }

  getIR() {
    return {
      fnArray: this.fnArray,
      argsArray: this.argsArray,
      length: this.length
    };
  }

  get _transfers() {
    const transfers = [];
    const {
      fnArray,
      argsArray,
      length
    } = this;

    for (let i = 0; i < length; i++) {
      switch (fnArray[i]) {
        case _util.OPS.paintInlineImageXObject:
        case _util.OPS.paintInlineImageXObjectGroup:
        case _util.OPS.paintImageMaskXObject:
          const arg = argsArray[i][0];
          ;

          if (!arg.cached) {
            transfers.push(arg.data.buffer);
          }

          break;
      }
    }

    return transfers;
  }

  flush(lastChunk = false) {
    this.optimizer.flush();
    const length = this.length;
    this._totalLength += length;

    this._streamSink.enqueue({
      fnArray: this.fnArray,
      argsArray: this.argsArray,
      lastChunk,
      length
    }, 1, this._transfers);

    this.dependencies.clear();
    this.fnArray.length = 0;
    this.argsArray.length = 0;
    this.weight = 0;
    this.optimizer.reset();
  }

}

exports.OperatorList = OperatorList;