commit 9a3f5541542346d5f37c6746d69f1431b4391b2b
author Hal Canary <halcanary@google.com> Mon Dec 10 19:59:07 2018 -0500
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Tue Dec 18 20:48:25 2018 +0000
tree b455cbf6f981ed309940b6dadf4d2b001d19f06c
parent 7dfe6d9ea73c1947832658999517d660a50d0b95

SkPDF: refactor streams, experimental threading

    All PDF Streams are immediatly serialized, and are never long-lived
    in memory.

    if EXPERIMENTAL fExecutor is set on the Document, streams are
    compressed in parallel.

    Results for PDFBigDocBench:

        without patch                    1807885.01 μs
        with    patch without executor   1802808.35 μs
        with    patch with    executor    246313.72 μs

    SkPDFStreamOut() function replaces SkPDFStream classes.

    Page resources are all serialized early.

    Several Document-level objects are serialzied early.

    SkUUID introduced as top-level object.

    Many {insert|append}ObjRef() converted to memory efficient
    {insert|append}Ref().

Bug: skia:8630
Change-Id: Ic336917d0c8b9ac1c2423b43bfe9b49a3533fbff
Reviewed-on: https://skia-review.googlesource.com/c/176588
Auto-Submit: Hal Canary <halcanary@google.com>
Reviewed-by: Herb Derby <herb@google.com>
Commit-Queue: Hal Canary <halcanary@google.com>

src/pdf/SkPDFDocumentPriv.h

diff --git a/src/pdf/SkPDFDocumentPriv.h b/src/pdf/SkPDFDocumentPriv.h
index c23e026..27810dd 100644
--- a/src/pdf/SkPDFDocumentPriv.h
+++ b/src/pdf/SkPDFDocumentPriv.h
@@ -8,13 +8,17 @@
 #define SkPDFDocumentPriv_DEFINED
 
 #include "SkCanvas.h"
-#include "SkPDFDocument.h"
 #include "SkPDFCanon.h"
+#include "SkPDFDocument.h"
 #include "SkPDFFont.h"
 #include "SkPDFMetadata.h"
+#include "SkUUID.h"
+
+#include <atomic>
 
 class SkPDFDevice;
 class SkPDFTag;
+class SkExecutor;
 
 const char* SkPDFGetNodeIdKey();
 
@@ -31,23 +35,26 @@
 // Logically part of SkPDFDocument (like SkPDFCanon), but separate to
 // keep similar functionality together.
 struct SkPDFObjectSerializer {
-    int fNextObjectNumber = 1;
+    std::atomic<int> fNextObjectNumber = {1};
+    SkPDFIndirectReference reserve() { return SkPDFIndirectReference{fNextObjectNumber++}; }
     SkPDFOffsetMap fOffsets;
-    sk_sp<SkPDFObject> fInfoDict;
     size_t fBaseOffset = SIZE_MAX;
 
     SkPDFObjectSerializer();
     ~SkPDFObjectSerializer();
-    SkPDFObjectSerializer(SkPDFObjectSerializer&&);
-    SkPDFObjectSerializer& operator=(SkPDFObjectSerializer&&);
+    SkPDFObjectSerializer(SkPDFObjectSerializer&&) = delete;
+    SkPDFObjectSerializer& operator=(SkPDFObjectSerializer&&) = delete;
     SkPDFObjectSerializer(const SkPDFObjectSerializer&) = delete;
     SkPDFObjectSerializer& operator=(const SkPDFObjectSerializer&) = delete;
 
     SkWStream* beginObject(SkPDFIndirectReference, SkWStream*);
     void endObject(SkWStream*);
-    void serializeHeader(SkWStream*, const SkPDF::Metadata&);
+    void serializeHeader(SkWStream*);
     void serializeObject(const sk_sp<SkPDFObject>&, SkWStream*);
-    void serializeFooter(SkWStream*, const sk_sp<SkPDFObject>, sk_sp<SkPDFObject>);
+    void serializeFooter(SkWStream*,
+                         SkPDFIndirectReference infoDict,
+                         SkPDFIndirectReference docCatalog,
+                         SkUUID uuid);
     SkPDFFileOffset offset(SkWStream*);
 };
 
@@ -73,7 +80,8 @@
        after calling serialize, since those changes will be too late.
      */
     SkPDFIndirectReference serialize(const sk_sp<SkPDFObject>&);
-    SkPDFIndirectReference emit(const SkPDFObject&);
+    SkPDFIndirectReference emit(const SkPDFObject&, SkPDFIndirectReference);
+    SkPDFIndirectReference emit(const SkPDFObject& o) { return this->emit(o, this->reserveRef()); }
     SkPDFCanon* canon() { return &fCanon; }
     const SkPDF::Metadata& metadata() const { return fMetadata; }
 
@@ -81,10 +89,12 @@
     // Returns -1 if no mark ID.
     int getMarkIdForNodeId(int nodeId);
 
-    SkPDFIndirectReference reserve();
+    SkPDFIndirectReference reserveRef();
     SkWStream* beginObject(SkPDFIndirectReference);
     void endObject();
 
+    SkExecutor* executor() const { return fExecutor; }
+
 private:
     sk_sp<SkPDFTag> recursiveBuildTagTree(const SkPDF::StructureElementNode& node,
                                           sk_sp<SkPDFTag> parent);
@@ -95,11 +105,13 @@
     std::vector<sk_sp<SkPDFDict>> fPages;
     sk_sp<SkPDFDict> fDests;
     sk_sp<SkPDFDevice> fPageDevice;
-    sk_sp<SkPDFObject> fID;
-    sk_sp<SkPDFObject> fXMP;
+    SkUUID fUUID;
+    SkPDFIndirectReference fInfoDict;
+    SkPDFIndirectReference fXMP;
     SkPDF::Metadata fMetadata;
     SkScalar fRasterScale = 1;
     SkScalar fInverseRasterScale = 1;
+    SkExecutor* fExecutor = nullptr;
 
     // For tagged PDFs.
 
@@ -110,7 +122,9 @@
     // A mapping from node ID to tag for fast lookup.
     SkTHashMap<int, sk_sp<SkPDFTag>> fNodeIdToTag;
 
-    int fOutstandingRefs = 0;
+    std::atomic<int> fOutstandingRefs = {0};
+    SkMutex fMutex;
+    SkSemaphore fSemaphore;
 
     void reset();
 };