Source code
Revision control
Copy as Markdown
Other Tools
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "gfxSVGGlyphs.h"
#include "mozilla/BasePrincipal.h"
#include "mozilla/LoadInfo.h"
#include "mozilla/NullPrincipal.h"
#include "mozilla/PresShell.h"
#include "mozilla/SMILAnimationController.h"
#include "mozilla/SVGContextPaint.h"
#include "mozilla/SVGUtils.h"
#include "mozilla/dom/Document.h"
#include "mozilla/dom/Element.h"
#include "mozilla/dom/ImageTracker.h"
#include "mozilla/dom/SVGDocument.h"
#include "nsError.h"
#include "nsString.h"
#include "nsICategoryManager.h"
#include "nsIDocumentLoaderFactory.h"
#include "nsIDocumentViewer.h"
#include "nsIStreamListener.h"
#include "nsServiceManagerUtils.h"
#include "nsNetUtil.h"
#include "nsIInputStream.h"
#include "nsStringStream.h"
#include "nsStreamUtils.h"
#include "nsIPrincipal.h"
#include "nsContentUtils.h"
#include "gfxFont.h"
#include "gfxContext.h"
#include "harfbuzz/hb.h"
#include "zlib.h"
#define SVG_CONTENT_TYPE "image/svg+xml"_ns
#define UTF8_CHARSET "utf-8"_ns
using namespace mozilla;
using mozilla::dom::Document;
using mozilla::dom::Element;
gfxSVGGlyphs::gfxSVGGlyphs(hb_blob_t* aSVGTable, gfxFontEntry* aFontEntry)
: mSVGData(aSVGTable), mFontEntry(aFontEntry) {
unsigned int length;
const char* svgData = hb_blob_get_data(mSVGData, &length);
mHeader = reinterpret_cast<const Header*>(svgData);
mDocIndex = nullptr;
if (sizeof(Header) <= length && uint16_t(mHeader->mVersion) == 0 &&
uint64_t(mHeader->mDocIndexOffset) + 2 <= length) {
const DocIndex* docIndex =
reinterpret_cast<const DocIndex*>(svgData + mHeader->mDocIndexOffset);
// Limit the number of documents to avoid overflow
if (uint64_t(mHeader->mDocIndexOffset) + 2 +
uint16_t(docIndex->mNumEntries) * sizeof(IndexEntry) <=
length) {
mDocIndex = docIndex;
}
}
}
gfxSVGGlyphs::~gfxSVGGlyphs() { hb_blob_destroy(mSVGData); }
void gfxSVGGlyphs::DidRefresh() { mFontEntry->NotifyGlyphsChanged(); }
/*
* Comparison operator for finding a range containing a given glyph ID. Simply
* checks whether |key| is less (greater) than every element of |range|, in
* which case return |key| < |range| (|key| > |range|). Otherwise |key| is in
* |range|, in which case return equality.
* The total ordering here is guaranteed by
* (1) the index ranges being disjoint; and
* (2) the (sole) key always being a singleton, so intersection => containment
* (note that this is wrong if we have more than one intersection or two
* sets intersecting of size > 1 -- so... don't do that)
*/
/* static */
int gfxSVGGlyphs::CompareIndexEntries(const void* aKey, const void* aEntry) {
const uint32_t key = *(uint32_t*)aKey;
const IndexEntry* entry = (const IndexEntry*)aEntry;
if (key < uint16_t(entry->mStartGlyph)) {
return -1;
}
if (key > uint16_t(entry->mEndGlyph)) {
return 1;
}
return 0;
}
gfxSVGGlyphsDocument* gfxSVGGlyphs::FindOrCreateGlyphsDocument(
uint32_t aGlyphId) {
if (!mDocIndex) {
// Invalid table
return nullptr;
}
IndexEntry* entry = (IndexEntry*)bsearch(
&aGlyphId, mDocIndex->mEntries, uint16_t(mDocIndex->mNumEntries),
sizeof(IndexEntry), CompareIndexEntries);
if (!entry) {
return nullptr;
}
return mGlyphDocs.WithEntryHandle(
entry->mDocOffset, [&](auto&& glyphDocsEntry) -> gfxSVGGlyphsDocument* {
if (!glyphDocsEntry) {
unsigned int length;
const uint8_t* data =
(const uint8_t*)hb_blob_get_data(mSVGData, &length);
if (entry->mDocOffset > 0 && uint64_t(mHeader->mDocIndexOffset) +
entry->mDocOffset +
entry->mDocLength <=
length) {
return glyphDocsEntry
.Insert(MakeUnique<gfxSVGGlyphsDocument>(
data + mHeader->mDocIndexOffset + entry->mDocOffset,
entry->mDocLength, this))
.get();
}
return nullptr;
}
return glyphDocsEntry->get();
});
}
nsresult gfxSVGGlyphsDocument::SetupPresentation() {
nsCOMPtr<nsIDocumentLoaderFactory> docLoaderFactory =
nsContentUtils::FindInternalDocumentViewer(SVG_CONTENT_TYPE);
NS_ASSERTION(docLoaderFactory, "Couldn't get DocumentLoaderFactory");
nsCOMPtr<nsIDocumentViewer> viewer;
nsresult rv = docLoaderFactory->CreateInstanceForDocument(
nullptr, mDocument, nullptr, getter_AddRefs(viewer));
NS_ENSURE_SUCCESS(rv, rv);
auto upem = mOwner->FontEntry()->UnitsPerEm();
rv = viewer->Init(nullptr, LayoutDeviceIntRect(0, 0, upem, upem), nullptr);
if (NS_SUCCEEDED(rv)) {
rv = viewer->Open(nullptr, nullptr);
NS_ENSURE_SUCCESS(rv, rv);
}
RefPtr<PresShell> presShell = viewer->GetPresShell();
if (!presShell->DidInitialize()) {
rv = presShell->Initialize();
NS_ENSURE_SUCCESS(rv, rv);
}
mDocument->FlushPendingNotifications(FlushType::Layout);
if (mDocument->HasAnimationController()) {
mDocument->GetAnimationController()->Resume(SMILTimeContainer::PAUSE_IMAGE);
}
mDocument->ImageTracker()->SetAnimatingState(true);
mViewer = viewer;
mPresShell = presShell;
mPresShell->AddPostRefreshObserver(this);
return NS_OK;
}
void gfxSVGGlyphsDocument::DidRefresh() { mOwner->DidRefresh(); }
/**
* Walk the DOM tree to find all glyph elements and insert them into the lookup
* table
* @param aElem The element to search from
*/
void gfxSVGGlyphsDocument::FindGlyphElements(Element* aElem) {
for (nsIContent* child = aElem->GetLastChild(); child;
child = child->GetPreviousSibling()) {
if (!child->IsElement()) {
continue;
}
FindGlyphElements(child->AsElement());
}
InsertGlyphId(aElem);
}
/**
* If there exists an SVG glyph with the specified glyph id, render it and
* return true If no such glyph exists, or in the case of an error return false
* @param aContext The thebes aContext to draw to
* @param aGlyphId The glyph id
* @return true iff rendering succeeded
*/
void gfxSVGGlyphs::RenderGlyph(gfxContext* aContext, uint32_t aGlyphId,
SVGContextPaint* aContextPaint) {
gfxContextAutoSaveRestore aContextRestorer(aContext);
Element* glyph = mGlyphIdMap.Get(aGlyphId);
MOZ_ASSERT(glyph, "No glyph element. Should check with HasSVGGlyph() first!");
AutoSetRestoreSVGContextPaint autoSetRestore(aContextPaint,
glyph->OwnerDoc());
SVGUtils::PaintSVGGlyph(glyph, aContext);
#if DEBUG
// This will not have any effect, because we're about to restore the state
// via the aContextRestorer destructor, but it prevents debug builds from
// asserting if it turns out that PaintSVGGlyph didn't actually do anything.
// This happens if the SVG document consists of just an image, and the image
// hasn't finished loading yet so we can't draw it.
aContext->SetOp(gfx::CompositionOp::OP_OVER);
#endif
}
bool gfxSVGGlyphs::GetGlyphExtents(uint32_t aGlyphId,
const gfxMatrix& aSVGToAppSpace,
gfxRect* aResult) {
Element* glyph = mGlyphIdMap.Get(aGlyphId);
NS_ASSERTION(glyph,
"No glyph element. Should check with HasSVGGlyph() first!");
return SVGUtils::GetSVGGlyphExtents(glyph, aSVGToAppSpace, aResult);
}
Element* gfxSVGGlyphs::GetGlyphElement(uint32_t aGlyphId) {
return mGlyphIdMap.LookupOrInsertWith(aGlyphId, [&] {
Element* elem = nullptr;
if (gfxSVGGlyphsDocument* set = FindOrCreateGlyphsDocument(aGlyphId)) {
elem = set->GetGlyphElement(aGlyphId);
}
return elem;
});
}
bool gfxSVGGlyphs::HasSVGGlyph(uint32_t aGlyphId) {
return !!GetGlyphElement(aGlyphId);
}
size_t gfxSVGGlyphs::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const {
// We don't include the size of mSVGData here, because (depending on the
// font backend implementation) it will either wrap a block of data owned
// by the system (and potentially shared), or a table that's in our font
// table cache and therefore already counted.
size_t result = aMallocSizeOf(this) +
mGlyphDocs.ShallowSizeOfExcludingThis(aMallocSizeOf) +
mGlyphIdMap.ShallowSizeOfExcludingThis(aMallocSizeOf);
for (const auto& entry : mGlyphDocs.Values()) {
result += entry->SizeOfIncludingThis(aMallocSizeOf);
}
return result;
}
Element* gfxSVGGlyphsDocument::GetGlyphElement(uint32_t aGlyphId) {
return mGlyphIdMap.Get(aGlyphId);
}
gfxSVGGlyphsDocument::gfxSVGGlyphsDocument(const uint8_t* aBuffer,
uint32_t aBufLen,
gfxSVGGlyphs* aSVGGlyphs)
: mOwner(aSVGGlyphs) {
if (aBufLen >= 14 && aBuffer[0] == 31 && aBuffer[1] == 139) {
// It's a gzip-compressed document; decompress it before parsing.
// The original length (modulo 2^32) is found in the last 4 bytes
// of the data, stored in little-endian format. We read it as
// individual bytes to avoid possible alignment issues.
// (Note that if the original length was >2^32, then origLen here
// will be incorrect; but then the inflate() call will not return
// Z_STREAM_END and we'll bail out safely.)
size_t origLen = (size_t(aBuffer[aBufLen - 1]) << 24) +
(size_t(aBuffer[aBufLen - 2]) << 16) +
(size_t(aBuffer[aBufLen - 3]) << 8) +
size_t(aBuffer[aBufLen - 4]);
AutoTArray<uint8_t, 4096> outBuf;
if (outBuf.SetLength(origLen, mozilla::fallible)) {
z_stream s = {0};
s.next_in = const_cast<Byte*>(aBuffer);
s.avail_in = aBufLen;
s.next_out = outBuf.Elements();
s.avail_out = outBuf.Length();
// The magic number 16 here is the zlib flag to expect gzip format,
if (Z_OK == inflateInit2(&s, 16 + MAX_WBITS)) {
int result = inflate(&s, Z_FINISH);
if (Z_STREAM_END == result) {
MOZ_ASSERT(size_t(s.next_out - outBuf.Elements()) == origLen);
ParseDocument(outBuf.Elements(), outBuf.Length());
} else {
NS_WARNING("Failed to decompress SVG glyphs document");
}
inflateEnd(&s);
}
} else {
NS_WARNING("Failed to allocate memory for SVG glyphs document");
}
} else {
ParseDocument(aBuffer, aBufLen);
}
if (!mDocument) {
NS_WARNING("Could not parse SVG glyphs document");
return;
}
Element* root = mDocument->GetRootElement();
if (!root) {
NS_WARNING("Could not parse SVG glyphs document");
return;
}
nsresult rv = SetupPresentation();
if (NS_FAILED(rv)) {
NS_WARNING("Couldn't setup presentation for SVG glyphs document");
return;
}
FindGlyphElements(root);
}
gfxSVGGlyphsDocument::~gfxSVGGlyphsDocument() {
if (mDocument) {
mDocument->OnPageHide(false, nullptr);
}
if (mPresShell) {
mPresShell->RemovePostRefreshObserver(this);
}
if (mViewer) {
mViewer->Close(nullptr);
mViewer->Destroy();
}
}
static nsresult CreateBufferedStream(const uint8_t* aBuffer, uint32_t aBufLen,
nsCOMPtr<nsIInputStream>& aResult) {
nsCOMPtr<nsIInputStream> stream;
nsresult rv = NS_NewByteInputStream(
getter_AddRefs(stream),
Span(reinterpret_cast<const char*>(aBuffer), aBufLen),
NS_ASSIGNMENT_DEPEND);
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIInputStream> aBufferedStream;
if (!NS_InputStreamIsBuffered(stream)) {
rv = NS_NewBufferedInputStream(getter_AddRefs(aBufferedStream),
stream.forget(), 4096);
NS_ENSURE_SUCCESS(rv, rv);
stream = aBufferedStream;
}
aResult = stream;
return NS_OK;
}
nsresult gfxSVGGlyphsDocument::ParseDocument(const uint8_t* aBuffer,
uint32_t aBufLen) {
// Mostly pulled from nsDOMParser::ParseFromStream
nsCOMPtr<nsIInputStream> stream;
nsresult rv = CreateBufferedStream(aBuffer, aBufLen, stream);
NS_ENSURE_SUCCESS(rv, rv);
// We just need a dummy URI.
nsCOMPtr<nsIURI> uri;
rv = NS_NewURI(getter_AddRefs(uri), "moz-svg-glyphs://"_ns);
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIPrincipal> principal =
NullPrincipal::CreateWithoutOriginAttributes();
RefPtr<Document> document;
rv = NS_NewDOMDocument(getter_AddRefs(document),
u""_ns, // aNamespaceURI
u""_ns, // aQualifiedName
nullptr, // aDoctype
uri, uri, principal,
false, // aLoadedAsData
nullptr, // aEventObject
DocumentFlavorSVG);
NS_ENSURE_SUCCESS(rv, rv);
nsCOMPtr<nsIChannel> channel;
rv = NS_NewInputStreamChannel(
getter_AddRefs(channel), uri,
nullptr, // aStream
principal, nsILoadInfo::SEC_FORCE_INHERIT_PRINCIPAL,
nsIContentPolicy::TYPE_OTHER, SVG_CONTENT_TYPE, UTF8_CHARSET);
NS_ENSURE_SUCCESS(rv, rv);
// Set this early because various decisions during page-load depend on it.
document->SetIsBeingUsedAsImage();
document->SetIsSVGGlyphsDocument();
document->SetReadyStateInternal(Document::READYSTATE_UNINITIALIZED);
nsCOMPtr<nsIStreamListener> listener;
rv = document->StartDocumentLoad("external-resource", channel,
nullptr, // aLoadGroup
nullptr, // aContainer
getter_AddRefs(listener), true /* aReset */);
if (NS_FAILED(rv) || !listener) {
return NS_ERROR_FAILURE;
}
rv = listener->OnStartRequest(channel);
if (NS_FAILED(rv)) {
channel->Cancel(rv);
}
nsresult status;
channel->GetStatus(&status);
if (NS_SUCCEEDED(rv) && NS_SUCCEEDED(status)) {
rv = listener->OnDataAvailable(channel, stream, 0, aBufLen);
if (NS_FAILED(rv)) {
channel->Cancel(rv);
}
channel->GetStatus(&status);
}
rv = listener->OnStopRequest(channel, status);
NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
document.swap(mDocument);
return NS_OK;
}
void gfxSVGGlyphsDocument::InsertGlyphId(Element* aGlyphElement) {
nsAutoString glyphIdStr;
static const uint32_t glyphPrefixLength = 5;
// The maximum glyph ID is 65535 so the maximum length of the numeric part
// is 5.
if (!aGlyphElement->GetAttr(nsGkAtoms::id, glyphIdStr) ||
!StringBeginsWith(glyphIdStr, u"glyph"_ns) ||
glyphIdStr.Length() > glyphPrefixLength + 5) {
return;
}
uint32_t id = 0;
for (uint32_t i = glyphPrefixLength; i < glyphIdStr.Length(); ++i) {
char16_t ch = glyphIdStr.CharAt(i);
if (ch < '0' || ch > '9') {
return;
}
if (ch == '0' && i == glyphPrefixLength) {
return;
}
id = id * 10 + (ch - '0');
}
mGlyphIdMap.InsertOrUpdate(id, aGlyphElement);
}
size_t gfxSVGGlyphsDocument::SizeOfIncludingThis(
mozilla::MallocSizeOf aMallocSizeOf) const {
return aMallocSizeOf(this) +
mGlyphIdMap.ShallowSizeOfExcludingThis(aMallocSizeOf);
}