Move SkReadBuffer.h and SkReader32.h out of include.

R=mtklein@google.com, reed@google.com

Author: halcanary@google.com

Review URL: https://codereview.chromium.org/481053002

1 files changed, 160 insertions, 0 deletions

diff --git a/src/core/SkReader32.h b/src/core/SkReader32.h
new file mode 100644
index 0000000000..3d874d170a
--- /dev/null
+++ b/src/core/SkReader32.h
@@ -0,0 +1,160 @@
+
+/*
+ * Copyright 2008 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#ifndef SkReader32_DEFINED
+#define SkReader32_DEFINED
+
+#include "SkMatrix.h"
+#include "SkPath.h"
+#include "SkRegion.h"
+#include "SkRRect.h"
+#include "SkScalar.h"
+
+class SkString;
+
+class SkReader32 : SkNoncopyable {
+public:
+    SkReader32() : fCurr(NULL), fStop(NULL), fBase(NULL) {}
+    SkReader32(const void* data, size_t size)  {
+        this->setMemory(data, size);
+    }
+
+    void setMemory(const void* data, size_t size) {
+        SkASSERT(ptr_align_4(data));
+        SkASSERT(SkAlign4(size) == size);
+
+        fBase = fCurr = (const char*)data;
+        fStop = (const char*)data + size;
+    }
+
+    size_t size() const { return fStop - fBase; }
+    size_t offset() const { return fCurr - fBase; }
+    bool eof() const { return fCurr >= fStop; }
+    const void* base() const { return fBase; }
+    const void* peek() const { return fCurr; }
+
+    size_t available() const { return fStop - fCurr; }
+    bool isAvailable(size_t size) const { return size <= this->available(); }
+
+    void rewind() { fCurr = fBase; }
+
+    void setOffset(size_t offset) {
+        SkASSERT(SkAlign4(offset) == offset);
+        SkASSERT(offset <= this->size());
+        fCurr = fBase + offset;
+    }
+
+    bool readBool() { return this->readInt() != 0; }
+
+    int32_t readInt() {
+        SkASSERT(ptr_align_4(fCurr));
+        int32_t value = *(const int32_t*)fCurr;
+        fCurr += sizeof(value);
+        SkASSERT(fCurr <= fStop);
+        return value;
+    }
+
+    void* readPtr() {
+        void* ptr;
+        // we presume this "if" is resolved at compile-time
+        if (4 == sizeof(void*)) {
+            ptr = *(void**)fCurr;
+        } else {
+            memcpy(&ptr, fCurr, sizeof(void*));
+        }
+        fCurr += sizeof(void*);
+        return ptr;
+    }
+
+    SkScalar readScalar() {
+        SkASSERT(ptr_align_4(fCurr));
+        SkScalar value = *(const SkScalar*)fCurr;
+        fCurr += sizeof(value);
+        SkASSERT(fCurr <= fStop);
+        return value;
+    }
+
+    const void* skip(size_t size) {
+        SkASSERT(ptr_align_4(fCurr));
+        const void* addr = fCurr;
+        fCurr += SkAlign4(size);
+        SkASSERT(fCurr <= fStop);
+        return addr;
+    }
+
+    template <typename T> const T& skipT() {
+        SkASSERT(SkAlign4(sizeof(T)) == sizeof(T));
+        return *(const T*)this->skip(sizeof(T));
+    }
+
+    void read(void* dst, size_t size) {
+        SkASSERT(0 == size || dst != NULL);
+        SkASSERT(ptr_align_4(fCurr));
+        memcpy(dst, fCurr, size);
+        fCurr += SkAlign4(size);
+        SkASSERT(fCurr <= fStop);
+    }
+
+    uint8_t readU8() { return (uint8_t)this->readInt(); }
+    uint16_t readU16() { return (uint16_t)this->readInt(); }
+    int32_t readS32() { return this->readInt(); }
+    uint32_t readU32() { return this->readInt(); }
+
+    bool readPath(SkPath* path) {
+        return this->readObjectFromMemory(path);
+    }
+
+    bool readMatrix(SkMatrix* matrix) {
+        return this->readObjectFromMemory(matrix);
+    }
+
+    bool readRRect(SkRRect* rrect) {
+        return this->readObjectFromMemory(rrect);
+    }
+
+    bool readRegion(SkRegion* rgn) {
+        return this->readObjectFromMemory(rgn);
+    }
+
+    /**
+     *  Read the length of a string (written by SkWriter32::writeString) into
+     *  len (if len is not NULL) and return the null-ternimated address of the
+     *  string within the reader's buffer.
+     */
+    const char* readString(size_t* len = NULL);
+
+    /**
+     *  Read the string (written by SkWriter32::writeString) and return it in
+     *  copy (if copy is not null). Return the length of the string.
+     */
+    size_t readIntoString(SkString* copy);
+
+private:
+    template <typename T> bool readObjectFromMemory(T* obj) {
+        size_t size = obj->readFromMemory(this->peek(), this->available());
+        // If readFromMemory() fails (which means that available() was too small), it returns 0
+        bool success = (size > 0) && (size <= this->available()) && (SkAlign4(size) == size);
+        // In case of failure, we want to skip to the end
+        (void)this->skip(success ? size : this->available());
+        return success;
+    }
+
+    // these are always 4-byte aligned
+    const char* fCurr;  // current position within buffer
+    const char* fStop;  // end of buffer
+    const char* fBase;  // beginning of buffer
+
+#ifdef SK_DEBUG
+    static bool ptr_align_4(const void* ptr) {
+        return (((const char*)ptr - (const char*)NULL) & 3) == 0;
+    }
+#endif
+};
+
+#endif