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      1 
      2 /*
      3  * Copyright 2010 The Android Open Source Project
      4  *
      5  * Use of this source code is governed by a BSD-style license that can be
      6  * found in the LICENSE file.
      7  */
      8 
      9 
     10 #include "SkPDFCatalog.h"
     11 #include "SkPDFTypes.h"
     12 #include "SkStream.h"
     13 #include "SkTypes.h"
     14 
     15 SkPDFCatalog::SkPDFCatalog(SkPDFDocument::Flags flags)
     16     : fFirstPageCount(0),
     17       fNextObjNum(1),
     18       fNextFirstPageObjNum(0),
     19       fDocumentFlags(flags) {
     20 }
     21 
     22 SkPDFCatalog::~SkPDFCatalog() {
     23     fSubstituteResourcesRemaining.safeUnrefAll();
     24     fSubstituteResourcesFirstPage.safeUnrefAll();
     25 }
     26 
     27 SkPDFObject* SkPDFCatalog::addObject(SkPDFObject* obj, bool onFirstPage) {
     28     if (findObjectIndex(obj) != -1) {  // object already added
     29         return obj;
     30     }
     31     SkASSERT(fNextFirstPageObjNum == 0);
     32     if (onFirstPage) {
     33         fFirstPageCount++;
     34     }
     35 
     36     struct Rec newEntry(obj, onFirstPage);
     37     fCatalog.append(1, &newEntry);
     38     return obj;
     39 }
     40 
     41 size_t SkPDFCatalog::setFileOffset(SkPDFObject* obj, off_t offset) {
     42     int objIndex = assignObjNum(obj) - 1;
     43     SkASSERT(fCatalog[objIndex].fObjNumAssigned);
     44     SkASSERT(fCatalog[objIndex].fFileOffset == 0);
     45     fCatalog[objIndex].fFileOffset = offset;
     46 
     47     return getSubstituteObject(obj)->getOutputSize(this, true);
     48 }
     49 
     50 void SkPDFCatalog::emitObjectNumber(SkWStream* stream, SkPDFObject* obj) {
     51     stream->writeDecAsText(assignObjNum(obj));
     52     stream->writeText(" 0");  // Generation number is always 0.
     53 }
     54 
     55 size_t SkPDFCatalog::getObjectNumberSize(SkPDFObject* obj) {
     56     SkDynamicMemoryWStream buffer;
     57     emitObjectNumber(&buffer, obj);
     58     return buffer.getOffset();
     59 }
     60 
     61 int SkPDFCatalog::findObjectIndex(SkPDFObject* obj) const {
     62     for (int i = 0; i < fCatalog.count(); i++) {
     63         if (fCatalog[i].fObject == obj) {
     64             return i;
     65         }
     66     }
     67     // If it's not in the main array, check if it's a substitute object.
     68     for (int i = 0; i < fSubstituteMap.count(); ++i) {
     69         if (fSubstituteMap[i].fSubstitute == obj) {
     70             return findObjectIndex(fSubstituteMap[i].fOriginal);
     71         }
     72     }
     73     return -1;
     74 }
     75 
     76 int SkPDFCatalog::assignObjNum(SkPDFObject* obj) {
     77     int pos = findObjectIndex(obj);
     78     // If this assert fails, it means you probably forgot to add an object
     79     // to the resource list.
     80     SkASSERT(pos >= 0);
     81     uint32_t currentIndex = pos;
     82     if (fCatalog[currentIndex].fObjNumAssigned) {
     83         return currentIndex + 1;
     84     }
     85 
     86     // First assignment.
     87     if (fNextFirstPageObjNum == 0) {
     88         fNextFirstPageObjNum = fCatalog.count() - fFirstPageCount + 1;
     89     }
     90 
     91     uint32_t objNum;
     92     if (fCatalog[currentIndex].fOnFirstPage) {
     93         objNum = fNextFirstPageObjNum;
     94         fNextFirstPageObjNum++;
     95     } else {
     96         objNum = fNextObjNum;
     97         fNextObjNum++;
     98     }
     99 
    100     // When we assign an object an object number, we put it in that array
    101     // offset (minus 1 because object number 0 is reserved).
    102     SkASSERT(!fCatalog[objNum - 1].fObjNumAssigned);
    103     if (objNum - 1 != currentIndex) {
    104         SkTSwap(fCatalog[objNum - 1], fCatalog[currentIndex]);
    105     }
    106     fCatalog[objNum - 1].fObjNumAssigned = true;
    107     return objNum;
    108 }
    109 
    110 int32_t SkPDFCatalog::emitXrefTable(SkWStream* stream, bool firstPage) {
    111     int first = -1;
    112     int last = fCatalog.count() - 1;
    113     // TODO(vandebo): Support linearized format.
    114     // int last = fCatalog.count() - fFirstPageCount - 1;
    115     // if (firstPage) {
    116     //     first = fCatalog.count() - fFirstPageCount;
    117     //     last = fCatalog.count() - 1;
    118     // }
    119 
    120     stream->writeText("xref\n");
    121     stream->writeDecAsText(first + 1);
    122     stream->writeText(" ");
    123     stream->writeDecAsText(last - first + 1);
    124     stream->writeText("\n");
    125 
    126     if (first == -1) {
    127         stream->writeText("0000000000 65535 f \n");
    128         first++;
    129     }
    130     for (int i = first; i <= last; i++) {
    131         // For 32 bits platforms, the maximum offset has to fit within off_t
    132         // which is a 32 bits signed integer on these platforms.
    133         SkDEBUGCODE(static const off_t kMaxOff = SK_MaxS32;)
    134         SkASSERT(fCatalog[i].fFileOffset > 0);
    135         SkASSERT(fCatalog[i].fFileOffset < kMaxOff);
    136         stream->writeBigDecAsText(fCatalog[i].fFileOffset, 10);
    137         stream->writeText(" 00000 n \n");
    138     }
    139 
    140     return fCatalog.count() + 1;
    141 }
    142 
    143 void SkPDFCatalog::setSubstitute(SkPDFObject* original,
    144                                  SkPDFObject* substitute) {
    145 #if defined(SK_DEBUG)
    146     // Sanity check: is the original already in substitute list?
    147     for (int i = 0; i < fSubstituteMap.count(); ++i) {
    148         if (original == fSubstituteMap[i].fSubstitute ||
    149             original == fSubstituteMap[i].fOriginal) {
    150             SkASSERT(false);
    151             return;
    152         }
    153     }
    154 #endif
    155     // Check if the original is on first page.
    156     bool onFirstPage = false;
    157     for (int i = 0; i < fCatalog.count(); ++i) {
    158         if (fCatalog[i].fObject == original) {
    159             onFirstPage = fCatalog[i].fOnFirstPage;
    160             break;
    161         }
    162 #if defined(SK_DEBUG)
    163         if (i == fCatalog.count() - 1) {
    164             SkASSERT(false);  // original not in catalog
    165             return;
    166         }
    167 #endif
    168     }
    169 
    170     SubstituteMapping newMapping(original, substitute);
    171     fSubstituteMap.append(1, &newMapping);
    172 
    173     // Add resource objects of substitute object to catalog.
    174     SkTSet<SkPDFObject*>* targetSet = getSubstituteList(onFirstPage);
    175     SkTSet<SkPDFObject*> newResourceObjects;
    176     newMapping.fSubstitute->getResources(*targetSet, &newResourceObjects);
    177     for (int i = 0; i < newResourceObjects.count(); ++i) {
    178         addObject(newResourceObjects[i], onFirstPage);
    179     }
    180     // mergeInto returns the number of duplicates.
    181     // If there are duplicates, there is a bug and we mess ref counting.
    182     SkDEBUGCODE(int duplicates =) targetSet->mergeInto(newResourceObjects);
    183     SkASSERT(duplicates == 0);
    184 }
    185 
    186 SkPDFObject* SkPDFCatalog::getSubstituteObject(SkPDFObject* object) {
    187     for (int i = 0; i < fSubstituteMap.count(); ++i) {
    188         if (object == fSubstituteMap[i].fOriginal) {
    189             return fSubstituteMap[i].fSubstitute;
    190         }
    191     }
    192     return object;
    193 }
    194 
    195 off_t SkPDFCatalog::setSubstituteResourcesOffsets(off_t fileOffset,
    196                                                   bool firstPage) {
    197     SkTSet<SkPDFObject*>* targetSet = getSubstituteList(firstPage);
    198     off_t offsetSum = fileOffset;
    199     for (int i = 0; i < targetSet->count(); ++i) {
    200         offsetSum += setFileOffset((*targetSet)[i], offsetSum);
    201     }
    202     return offsetSum - fileOffset;
    203 }
    204 
    205 void SkPDFCatalog::emitSubstituteResources(SkWStream *stream, bool firstPage) {
    206     SkTSet<SkPDFObject*>* targetSet = getSubstituteList(firstPage);
    207     for (int i = 0; i < targetSet->count(); ++i) {
    208         (*targetSet)[i]->emit(stream, this, true);
    209     }
    210 }
    211 
    212 SkTSet<SkPDFObject*>* SkPDFCatalog::getSubstituteList(bool firstPage) {
    213     return firstPage ? &fSubstituteResourcesFirstPage :
    214                        &fSubstituteResourcesRemaining;
    215 }
    216