Fix SkFILEStream.

Change-Id: I8c66e4e3e857227aed3d0bc497982f4c0d96d917
Reviewed-on: https://skia-review.googlesource.com/9498
Commit-Queue: Ben Wagner <bungeman@google.com>
Reviewed-by: Leon Scroggins <scroggo@google.com>

1 files changed, 53 insertions, 63 deletions

diff --git a/src/core/SkStream.cpp b/src/core/SkStream.cpp
index db9caee541..1435dab235 100644
--- a/src/core/SkStream.cpp
+++ b/src/core/SkStream.cpp
@@ -155,105 +155,95 @@ bool SkWStream::writeStream(SkStream* stream, size_t length) {
 
 ///////////////////////////////////////////////////////////////////////////////
 
-SkFILEStream::SkFILEStream(const char file[]) : fName(file), fOwnership(kCallerPasses_Ownership) {
-    fFILE = file ? sk_fopen(fName.c_str(), kRead_SkFILE_Flag) : nullptr;
-}
+SkFILEStream::SkFILEStream(std::shared_ptr<FILE> file, size_t size,
+                           size_t offset, size_t originalOffset)
+    : fFILE(std::move(file))
+    , fSize(size)
+    , fOffset(SkTMin(offset, fSize))
+    , fOriginalOffset(SkTMin(originalOffset, fSize))
+{ }
+
+SkFILEStream::SkFILEStream(std::shared_ptr<FILE> file, size_t size, size_t offset)
+    : SkFILEStream(std::move(file), size, offset, offset)
+{ }
+
+SkFILEStream::SkFILEStream(FILE* file)
+    : SkFILEStream(std::shared_ptr<FILE>(file, sk_fclose),
+                   file ? sk_fgetsize(file) : 0,
+                   file ? sk_ftell(file) : 0)
+{ }
 
-SkFILEStream::SkFILEStream(FILE* file, Ownership ownership)
-    : fFILE(file)
-    , fOwnership(ownership) {
-}
+
+SkFILEStream::SkFILEStream(const char path[])
+    : SkFILEStream(path ? sk_fopen(path, kRead_SkFILE_Flag) : nullptr)
+{ }
 
 SkFILEStream::~SkFILEStream() {
-    if (fFILE && fOwnership != kCallerRetains_Ownership) {
-        sk_fclose(fFILE);
-    }
+    this->close();
 }
 
-void SkFILEStream::setPath(const char path[]) {
-    fName.set(path);
-    if (fFILE) {
-        sk_fclose(fFILE);
-        fFILE = nullptr;
-    }
-    if (path) {
-        fFILE = sk_fopen(fName.c_str(), kRead_SkFILE_Flag);
-    }
+void SkFILEStream::close() {
+    fFILE.reset();
+    fSize = 0;
+    fOffset = 0;
 }
 
 size_t SkFILEStream::read(void* buffer, size_t size) {
-    if (fFILE) {
-        return sk_fread(buffer, size, fFILE);
+    if (size > fSize - fOffset) {
+        size = fSize - fOffset;
     }
-    return 0;
+    size_t bytesRead = size;
+    if (buffer) {
+        bytesRead = sk_qread(fFILE.get(), buffer, size, fOffset);
+    }
+    if (bytesRead == SIZE_MAX) {
+        return 0;
+    }
+    fOffset += bytesRead;
+    return bytesRead;
 }
 
 bool SkFILEStream::isAtEnd() const {
-    return sk_feof(fFILE);
+    if (fOffset == fSize) {
+        return true;
+    }
+    return fOffset >= sk_fgetsize(fFILE.get());
 }
 
 bool SkFILEStream::rewind() {
-    if (fFILE) {
-        if (sk_frewind(fFILE)) {
-            return true;
-        }
-        // we hit an error
-        sk_fclose(fFILE);
-        fFILE = nullptr;
-    }
-    return false;
+    // TODO: fOriginalOffset instead of 0.
+    fOffset = 0;
+    return true;
 }
 
 SkStreamAsset* SkFILEStream::duplicate() const {
-    if (nullptr == fFILE) {
-        return new SkMemoryStream();
-    }
-
-    if (fData.get()) {
-        return new SkMemoryStream(fData);
-    }
-
-    if (!fName.isEmpty()) {
-        std::unique_ptr<SkFILEStream> that(new SkFILEStream(fName.c_str()));
-        if (sk_fidentical(that->fFILE, this->fFILE)) {
-            return that.release();
-        }
-    }
-
-    fData = SkData::MakeFromFILE(fFILE);
-    if (nullptr == fData) {
-        return nullptr;
-    }
-    return new SkMemoryStream(fData);
+    // TODO: fOriginalOffset instead of 0.
+    return new SkFILEStream(fFILE, fSize, 0, fOriginalOffset);
 }
 
 size_t SkFILEStream::getPosition() const {
-    return sk_ftell(fFILE);
+    return fOffset;
 }
 
 bool SkFILEStream::seek(size_t position) {
-    return sk_fseek(fFILE, position);
+    fOffset = position > fSize ? fSize : position;
+    return true;
 }
 
 bool SkFILEStream::move(long offset) {
-    return sk_fmove(fFILE, offset);
+    return this->seek(fOffset + offset);
 }
 
 SkStreamAsset* SkFILEStream::fork() const {
-    std::unique_ptr<SkStreamAsset> that(this->duplicate());
-    that->seek(this->getPosition());
-    return that.release();
+    return new SkFILEStream(fFILE, fSize, fOffset, fOriginalOffset);
 }
 
 size_t SkFILEStream::getLength() const {
-    return sk_fgetsize(fFILE);
+    return fSize;
 }
 
 const void* SkFILEStream::getMemoryBase() {
-    if (nullptr == fData.get()) {
-        return nullptr;
-    }
-    return fData->data();
+    return nullptr;
 }
 
 ///////////////////////////////////////////////////////////////////////////////