update headers

ios/include/filaflat/Unflattener.h

@@ -0,0 +1,163 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef TNT_FILAFLAT_UNFLATTENER_H
+#define TNT_FILAFLAT_UNFLATTENER_H
+
+#include <utils/compiler.h>
+#include <utils/CString.h>
+
+#include <private/filament/Variant.h>
+
+#include <stdint.h>
+
+namespace filaflat {
+
+// Allow read operation from an Unflattenable. All READ operation MUST go through the Unflattener
+// since it checks boundaries before readind. All read operations return values MUST be verified,
+// never assume a read will succeed.
+class UTILS_PUBLIC Unflattener {
+public:
+    Unflattener() noexcept = default;
+
+    Unflattener(const uint8_t* src, const uint8_t* end)
+            : mSrc(src), mCursor(src), mEnd(end) {
+        assert_invariant(src && end);
+    }
+
+    Unflattener(Unflattener const& rhs) = default;
+
+    ~Unflattener() noexcept = default;
+
+    bool hasData() const noexcept {
+        return mCursor < mEnd;
+    }
+
+    inline bool willOverflow(size_t size) const noexcept {
+        return (mCursor + size) > mEnd;
+    }
+
+    void skipAlignmentPadding() {
+        const uint8_t padSize = (8 - (intptr_t(mCursor) % 8)) % 8;
+        mCursor += padSize;
+        assert_invariant(0 == (intptr_t(mCursor) % 8));
+    }
+
+    bool read(bool* b) noexcept {
+        if (willOverflow(1)) {
+            return false;
+        }
+        *b = mCursor[0];
+        mCursor += 1;
+        return true;
+    }
+
+    bool read(uint8_t* i) noexcept {
+        if (willOverflow(1)) {
+            return false;
+        }
+        *i = mCursor[0];
+        mCursor += 1;
+        return true;
+    }
+
+    bool read(filament::Variant* v) noexcept {
+        return read(&v->key);
+    }
+
+    bool read(uint16_t* i) noexcept {
+        if (willOverflow(2)) {
+            return false;
+        }
+        *i = 0;
+        *i |= mCursor[0];
+        *i |= mCursor[1] << 8;
+        mCursor += 2;
+        return true;
+    }
+
+    bool read(uint32_t* i) noexcept {
+        if (willOverflow(4)) {
+            return false;
+        }
+        *i = 0;
+        *i |= mCursor[0];
+        *i |= mCursor[1] << 8;
+        *i |= mCursor[2] << 16;
+        *i |= mCursor[3] << 24;
+        mCursor += 4;
+        return true;
+    }
+
+    bool read(uint64_t* i) noexcept {
+        if (willOverflow(8)) {
+            return false;
+        }
+        *i = 0;
+        *i |= static_cast<int64_t>(mCursor[0]);
+        *i |= static_cast<int64_t>(mCursor[1]) << 8;
+        *i |= static_cast<int64_t>(mCursor[2]) << 16;
+        *i |= static_cast<int64_t>(mCursor[3]) << 24;
+        *i |= static_cast<int64_t>(mCursor[4]) << 32;
+        *i |= static_cast<int64_t>(mCursor[5]) << 40;
+        *i |= static_cast<int64_t>(mCursor[6]) << 48;
+        *i |= static_cast<int64_t>(mCursor[7]) << 56;
+        mCursor += 8;
+        return true;
+    }
+
+    bool read(utils::CString* s) noexcept;
+
+    bool read(const char** blob, size_t* size) noexcept;
+
+    bool read(const char** s) noexcept;
+
+    bool read(float* f) noexcept {
+        if (willOverflow(4)) {
+            return false;
+        }
+        uint32_t i;
+        i = 0;
+        i |= mCursor[0];
+        i |= mCursor[1] << 8;
+        i |= mCursor[2] << 16;
+        i |= mCursor[3] << 24;
+        *f = reinterpret_cast<float&>(i);
+        mCursor += 4;
+        return true;
+    }
+
+    const uint8_t* getCursor() const noexcept {
+        return mCursor;
+    }
+
+    void setCursor(const uint8_t* cursor) noexcept {
+        if (mSrc <= cursor && cursor < mEnd) {
+            mCursor = cursor;
+        } else {
+            mCursor = mEnd;
+        }
+    }
+
+private:
+    const uint8_t* mSrc = nullptr;
+    const uint8_t* mCursor = nullptr;
+    const uint8_t* mEnd = nullptr;
+};
+
+} //namespace filaflat
+
+#endif // TNT_FILAFLAT_UNFLATTENER_H