work on the native parser, in progress, uploaded to have a backup

experimental/PdfViewer/pdfparser/native/SkNativeParsedPDF.cpp

-
 #include "SkNativeParsedPDF.h"
-
-SkNativeParsedPDF::SkNativeParsedPDF() {
-    // TODO(edisonn): Auto-generated constructor stub
-
-}
-
+#include "SkPdfNativeTokenizer.h"
+#include "SkPdfBasics.h"
+#include "SkPdfParser.h"
+#include "SkPdfObject.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "SkPdfFileTrailerDictionary_autogen.h"
+#include "SkPdfCatalogDictionary_autogen.h"
+#include "SkPdfPageObjectDictionary_autogen.h"
+#include "SkPdfPageTreeNodeDictionary_autogen.h"
+#include "SkPdfMapper_autogen.h"
+
+
+
+long getFileSize(const char* filename)
+{
+    struct stat stat_buf;
+    int rc = stat(filename, &stat_buf);
+    return rc == 0 ? stat_buf.st_size : -1;
+}
+
+unsigned char* lineHome(unsigned char* start, unsigned char* current) {
+    while (current > start && !isPdfEOL(*(current - 1))) {
+        current--;
+    }
+    return current;
+}
+
+unsigned char* previousLineHome(unsigned char* start, unsigned char* current) {
+    if (current > start && isPdfEOL(*(current - 1))) {
+        current--;
+    }
+
+    // allows CR+LF, LF+CR but not two CR+CR or LF+LF
+    if (current > start && isPdfEOL(*(current - 1)) && *current != *(current - 1)) {
+        current--;
+    }
+
+    while (current > start && !isPdfEOL(*(current - 1))) {
+        current--;
+    }
+
+    return current;
+}
+
+unsigned char* ignoreLine(unsigned char* current, unsigned char* end) {
+    while (current < end && !isPdfEOL(*current)) {
+        current++;
+    }
+    current++;
+    if (current < end && isPdfEOL(*current) && *current != *(current - 1)) {
+        current++;
+    }
+    return current;
+}
+
+
+// TODO(edisonn): NYI
+// TODO(edisonn): 3 constructuctors from URL, from stream, from file ...
+// TODO(edisonn): write one that accepts errors in the file and ignores/fixis them
+// TODO(edisonn): testing:
+// 1) run on a lot of file
+// 2) recoverable corupt file: remove endobj, endsteam, remove other keywords, use other white spaces, insert comments randomly, ...
+// 3) irrecoverable corrupt file
+SkNativeParsedPDF::SkNativeParsedPDF(const char* path) : fAllocator(new SkPdfAllocator()) {
+    FILE* file = fopen(path, "r");
+    fContentLength = getFileSize(path);
+    fFileContent = new unsigned char[fContentLength];
+    fread(fFileContent, fContentLength, 1, file);
+    fclose(file);
+    file = NULL;
+
+    unsigned char* eofLine = lineHome(fFileContent, fFileContent + fContentLength - 1);
+    unsigned char* xrefByteOffsetLine = previousLineHome(fFileContent, eofLine);
+    unsigned char* xrefstartKeywordLine = previousLineHome(fFileContent, xrefByteOffsetLine);
+
+    if (strcmp((char*)xrefstartKeywordLine, "startxref") != 0) {
+        // TODO(edisonn): report/issue
+    }
+
+    long xrefByteOffset = atol((const char*)xrefByteOffsetLine);
+
+    bool storeCatalog = true;
+    while (xrefByteOffset >= 0) {
+        unsigned char* trailerStart = readCrossReferenceSection(fFileContent + xrefByteOffset, xrefstartKeywordLine);
+        xrefByteOffset = readTrailer(trailerStart, xrefstartKeywordLine, storeCatalog);
+        storeCatalog = false;
+    }
+
+    // TODO(edisonn): warn/error expect fObjects[fRefCatalogId].fGeneration == fRefCatalogGeneration
+    // TODO(edisonn): security, verify that SkPdfCatalogDictionary is indeed using mapper
+    // load catalog
+    fRootCatalog = (SkPdfCatalogDictionary*)resolveReference(fRootCatalogRef);
+    SkPdfPageTreeNodeDictionary* tree = fRootCatalog->Pages(this);
+
+    fillPages(tree);
+
+    // now actually read all objects if we want, or do it lazyly
+    // and resolve references?... or not ...
+}
+
+// TODO(edisonn): NYI
 SkNativeParsedPDF::~SkNativeParsedPDF() {
-    // TODO(edisonn): Auto-generated destructor stub
-}
-
+    delete[] fFileContent;
+    delete fAllocator;
+}
+
+unsigned char* SkNativeParsedPDF::readCrossReferenceSection(unsigned char* xrefStart, unsigned char* trailerEnd) {
+    unsigned char* current = ignoreLine(xrefStart, trailerEnd);  // TODO(edisonn): verify next keyord is "xref", use nextObject here
+
+    SkPdfObject token;
+    while (current < trailerEnd) {
+        token.reset();
+        unsigned char* previous = current;
+        current = nextObject(current, trailerEnd, &token, NULL);
+        if (!token.isInteger()) {
+            return previous;
+        }
+
+        int startId = token.intValue();
+        token.reset();
+        current = nextObject(current, trailerEnd, &token, NULL);
+
+        if (!token.isInteger()) {
+            // TODO(edisonn): report/warning
+            return current;
+        }
+
+        int entries = token.intValue();
+
+        for (int i = 0; i < entries; i++) {
+            token.reset();
+            current = nextObject(current, trailerEnd, &token, NULL);
+            if (!token.isInteger()) {
+                // TODO(edisonn): report/warning
+                return current;
+            }
+            int offset = token.intValue();
+
+            token.reset();
+            current = nextObject(current, trailerEnd, &token, NULL);
+            if (!token.isInteger()) {
+                // TODO(edisonn): report/warning
+                return current;
+            }
+            int generation = token.intValue();
+
+            token.reset();
+            current = nextObject(current, trailerEnd, &token, NULL);
+            if (!token.isKeyword() || token.len() != 1 || (*token.c_str() != 'f' && *token.c_str() != 'n')) {
+                // TODO(edisonn): report/warning
+                return current;
+            }
+
+            addCrossSectionInfo(startId + i, generation, offset, *token.c_str() == 'f');
+        }
+    }
+    // TODO(edisonn): it should never get here? there is no trailer?
+    return current;
+}
+
+long SkNativeParsedPDF::readTrailer(unsigned char* trailerStart, unsigned char* trailerEnd, bool storeCatalog) {
+    unsigned char* current = ignoreLine(trailerStart, trailerEnd);  // TODO(edisonn): verify next keyord is "trailer" use nextObject here
+
+    SkPdfObject token;
+    current = nextObject(current, trailerEnd, &token, fAllocator);
+    SkPdfFileTrailerDictionary* trailer = (SkPdfFileTrailerDictionary*)&token;
+
+    if (storeCatalog) {
+        const SkPdfObject* ref = trailer->Root(NULL);
+        if (ref == NULL || !ref->isReference()) {
+            // TODO(edisonn): oops, we have to fix the corrup pdf file
+            return -1;
+        }
+        fRootCatalogRef = ref;
+    }
+
+    if (trailer->has_Prev()) {
+        return trailer->Prev(NULL);
+    }
+
+    return -1;
+}
+
+void SkNativeParsedPDF::addCrossSectionInfo(int id, int generation, int offset, bool isFreed) {
+    // TODO(edisonn): security here
+    while (fObjects.count() < id + 1) {
+        reset(fObjects.append());
+    }
+
+    fObjects[id].fOffset = offset;
+    fObjects[id].fObj = NULL;
+}
+
+SkPdfObject* SkNativeParsedPDF::readObject(int id/*, int expectedGeneration*/) const {
+    long startOffset = fObjects[id].fOffset;
+    //long endOffset = fObjects[id].fOffsetEnd;
+    // TODO(edisonn): use hinted endOffset
+    // TODO(edisonn): current implementation will result in a lot of memory usage
+    // to decrease memory usage, we wither need to be smart and know where objects end, and we will
+    // alocate only the chancks needed, or the tokenizer will not make copies, but then it needs to
+    // cache the results so it does not go twice on the same buffer
+    unsigned char* current = fFileContent + startOffset;
+    unsigned char* end = fFileContent + fContentLength;
+
+    SkPdfNativeTokenizer tokenizer(current, end - current, fMapper, fAllocator);
+
+    SkPdfObject idObj;
+    SkPdfObject generationObj;
+    SkPdfObject objKeyword;
+    SkPdfObject* dict = fAllocator->allocObject();
+
+    current = nextObject(current, end, &idObj, NULL);
+    if (current >= end) {
+        // TODO(edisonn): report warning/error
+        return NULL;
+    }
+
+    current = nextObject(current, end, &generationObj, NULL);
+    if (current >= end) {
+        // TODO(edisonn): report warning/error
+        return NULL;
+    }
+
+    current = nextObject(current, end, &objKeyword, NULL);
+    if (current >= end) {
+        // TODO(edisonn): report warning/error
+        return NULL;
+    }
+
+    if (!idObj.isInteger() || !generationObj.isInteger() || id != idObj.intValue()/* || generation != generationObj.intValue()*/) {
+        // TODO(edisonn): report warning/error
+    }
+
+    if (!objKeyword.isKeyword() || strcmp(objKeyword.c_str(), "obj") != 0) {
+        // TODO(edisonn): report warning/error
+    }
+
+    current = nextObject(current, end, dict, fAllocator);
+
+    // TODO(edisonn): report warning/error - verify last token is endobj
+
+    return dict;
+}
+
+void SkNativeParsedPDF::fillPages(SkPdfPageTreeNodeDictionary* tree) {
+    const SkPdfArray* kids = tree->Kids(this);
+    if (kids == NULL) {
+        *fPages.append() = (SkPdfPageObjectDictionary*)tree;
+        return;
+    }
+
+    int cnt = kids->size();
+    for (int i = 0; i < cnt; i++) {
+        const SkPdfObject* obj = resolveReference(kids->objAtAIndex(i));
+        if (fMapper->mapPageObjectDictionary(obj) != kPageObjectDictionary_SkPdfObjectType) {
+            *fPages.append() = (SkPdfPageObjectDictionary*)obj;
+        } else {
+            // TODO(edisonn): verify that it is a page tree indeed
+            fillPages((SkPdfPageTreeNodeDictionary*)obj);
+        }
+    }
+}
+
+int SkNativeParsedPDF::pages() const {
+    return fPages.count();
+}
+
+SkPdfResourceDictionary* SkNativeParsedPDF::pageResources(int page) {
+    return fPages[page]->Resources(this);
+}
+
+// TODO(edisonn): Partial implemented. Move the logics directly in the code generator for inheritable and default value?
+SkRect SkNativeParsedPDF::MediaBox(int page) const {
+    SkPdfPageObjectDictionary* current = fPages[page];
+    while (!current->has_MediaBox() && current->has_Parent()) {
+        current = (SkPdfPageObjectDictionary*)current->Parent(this);
+    }
+    if (current) {
+        return current->MediaBox(this);
+    }
+    return SkRect::MakeEmpty();
+}
+
+// TODO(edisonn): stream or array ... ? for now only array
+SkPdfNativeTokenizer* SkNativeParsedPDF::tokenizerOfPage(int page) const {
+    if (fPages[page]->isContentsAStream(this)) {
+        return tokenizerOfStream(fPages[page]->getContentsAsStream(this));
+    } else {
+        // TODO(edisonn): NYI, we need to concatenate all streams in the array or make the tokenizer smart
+        // so we don't allocate new memory
+        return NULL;
+    }
+}
+
+SkPdfNativeTokenizer* SkNativeParsedPDF::tokenizerOfStream(SkPdfObject* stream) const {
+    if (stream == NULL) {
+        return NULL;
+    }
+
+    return new SkPdfNativeTokenizer(stream, fMapper, fAllocator);
+}
+
+// TODO(edisonn): NYI
+SkPdfNativeTokenizer* SkNativeParsedPDF::tokenizerOfBuffer(unsigned char* buffer, size_t len) const {
+    // warning does not track two calls in the same buffer! the buffer is updated!
+    // make a clean copy if needed!
+    return new SkPdfNativeTokenizer(buffer, len, fMapper, fAllocator);
+}
+
+size_t SkNativeParsedPDF::objects() const {
+    return fObjects.count();
+}
+
+SkPdfObject* SkNativeParsedPDF::object(int i) {
+    SkASSERT(!(i < 0 || i > fObjects.count()));
+
+    if (i < 0 || i > fObjects.count()) {
+        return NULL;
+    }
+
+    if (fObjects[i].fObj == NULL) {
+        // TODO(edisonn): when we read the cross reference sections, store the start of the next object
+        // and fill fOffsetEnd
+        fObjects[i].fObj = readObject(i);
+    }
+
+    return fObjects[i].fObj;
+}
+
+const SkPdfMapper* SkNativeParsedPDF::mapper() const {
+    return fMapper;
+}
+
+SkPdfReal* SkNativeParsedPDF::createReal(double value) const {
+    SkPdfObject* obj = fAllocator->allocObject();
+    SkPdfObject::makeReal(value, obj);
+    return (SkPdfReal*)obj;
+}
+
+SkPdfInteger* SkNativeParsedPDF::createInteger(int value) const {
+    SkPdfObject* obj = fAllocator->allocObject();
+    SkPdfObject::makeInteger(value, obj);
+    return (SkPdfInteger*)obj;
+}
+
+SkPdfString* SkNativeParsedPDF::createString(unsigned char* sz, size_t len) const {
+    SkPdfObject* obj = fAllocator->allocObject();
+    SkPdfObject::makeString(sz, len, obj);
+    return (SkPdfString*)obj;
+}
+
+PdfContext* gPdfContext = NULL;
+
+void SkNativeParsedPDF::drawPage(int page, SkCanvas* canvas) {
+    SkPdfNativeTokenizer* tokenizer = tokenizerOfPage(page);
+
+    PdfContext pdfContext(this);
+    pdfContext.fOriginalMatrix = SkMatrix::I();
+    pdfContext.fGraphicsState.fResources = pageResources(page);
+
+    gPdfContext = &pdfContext;
+
+    // TODO(edisonn): get matrix stuff right.
+    // TODO(edisonn): add DPI/scale/zoom.
+    SkScalar z = SkIntToScalar(0);
+    SkRect rect = MediaBox(page);
+    SkScalar w = rect.width();
+    SkScalar h = rect.height();
+
+    SkPoint pdfSpace[4] = {SkPoint::Make(z, z), SkPoint::Make(w, z), SkPoint::Make(w, h), SkPoint::Make(z, h)};
+//                SkPoint skiaSpace[4] = {SkPoint::Make(z, h), SkPoint::Make(w, h), SkPoint::Make(w, z), SkPoint::Make(z, z)};
+
+    // TODO(edisonn): add flag for this app to create sourunding buffer zone
+    // TODO(edisonn): add flagg for no clipping.
+    // Use larger image to make sure we do not draw anything outside of page
+    // could be used in tests.
+
+#ifdef PDF_DEBUG_3X
+    SkPoint skiaSpace[4] = {SkPoint::Make(w+z, h+h), SkPoint::Make(w+w, h+h), SkPoint::Make(w+w, h+z), SkPoint::Make(w+z, h+z)};
+#else
+    SkPoint skiaSpace[4] = {SkPoint::Make(z, h), SkPoint::Make(w, h), SkPoint::Make(w, z), SkPoint::Make(z, z)};
+#endif
+    //SkPoint pdfSpace[2] = {SkPoint::Make(z, z), SkPoint::Make(w, h)};
+    //SkPoint skiaSpace[2] = {SkPoint::Make(w, z), SkPoint::Make(z, h)};
+
+    //SkPoint pdfSpace[2] = {SkPoint::Make(z, z), SkPoint::Make(z, h)};
+    //SkPoint skiaSpace[2] = {SkPoint::Make(z, h), SkPoint::Make(z, z)};
+
+    //SkPoint pdfSpace[3] = {SkPoint::Make(z, z), SkPoint::Make(z, h), SkPoint::Make(w, h)};
+    //SkPoint skiaSpace[3] = {SkPoint::Make(z, h), SkPoint::Make(z, z), SkPoint::Make(w, 0)};
+
+    SkAssertResult(pdfContext.fOriginalMatrix.setPolyToPoly(pdfSpace, skiaSpace, 4));
+    SkTraceMatrix(pdfContext.fOriginalMatrix, "Original matrix");
+
+
+    pdfContext.fGraphicsState.fMatrix = pdfContext.fOriginalMatrix;
+    pdfContext.fGraphicsState.fMatrixTm = pdfContext.fGraphicsState.fMatrix;
+    pdfContext.fGraphicsState.fMatrixTlm = pdfContext.fGraphicsState.fMatrix;
+
+    canvas->setMatrix(pdfContext.fOriginalMatrix);
+
+#ifndef PDF_DEBUG_NO_PAGE_CLIPING
+    canvas->clipRect(SkRect::MakeXYWH(z, z, w, h), SkRegion::kIntersect_Op, true);
+#endif
+
+// erase with red before?
+//        SkPaint paint;
+//        paint.setColor(SK_ColorRED);
+//        canvas->drawRect(rect, paint);
+
+    PdfMainLooper looper(NULL, tokenizer, &pdfContext, canvas);
+    looper.loop();
+
+    delete tokenizer;
+
+    canvas->flush();
+}
+
+SkPdfAllocator* SkNativeParsedPDF::allocator() const {
+    return fAllocator;
+}
+
+SkPdfObject* SkNativeParsedPDF::resolveReference(SkPdfObject* ref) const {
+    return (SkPdfObject*)resolveReference((const SkPdfObject*)ref);
+}
+
+// TODO(edisonn): fix infinite loop if ref to itself!
+// TODO(edisonn): perf, fix refs at load, and resolve will simply return fResolvedReference?
+SkPdfObject* SkNativeParsedPDF::resolveReference(const SkPdfObject* ref) const {
+    if (ref && ref->isReference()) {
+        int id = ref->referenceId();
+        // TODO(edisonn): generation/updates not supported now
+        //int gen = ref->referenceGeneration();
+
+        SkASSERT(!(id < 0 || id > fObjects.count()));
+
+        if (id < 0 || id > fObjects.count()) {
+            return NULL;
+        }
+
+        // TODO(edisonn): verify id and gen expected
+
+        if (fObjects[id].fResolvedReference != NULL) {
+            return fObjects[id].fResolvedReference;
+        }
+
+        if (fObjects[id].fObj == NULL) {
+            fObjects[id].fObj = readObject(id);
+        }
+
+        if (fObjects[id].fResolvedReference == NULL) {
+            if (!fObjects[id].fObj->isReference()) {
+                fObjects[id].fResolvedReference = fObjects[id].fObj;
+            } else {
+                fObjects[id].fResolvedReference = resolveReference(fObjects[id].fObj);
+            }
+        }
+
+        return fObjects[id].fResolvedReference;
+    }
+    // TODO(edisonn): fix the mess with const, probably we need to remove it pretty much everywhere
+    return (SkPdfObject*)ref;
+}