Initial work

external/android-emugl/shared/emugl/common/pod_vector.cpp

@@ -0,0 +1,150 @@
+// Copyright (C) 2014 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.
+
+#include "emugl/common/pod_vector.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+#define USE_MALLOC_USABLE_SIZE 0
+
+namespace emugl {
+
+static inline void swapPointers(char** p1, char** p2) {
+    char* tmp = *p1;
+    *p1 = *p2;
+    *p2 = tmp;
+}
+
+PodVectorBase::PodVectorBase(const PodVectorBase& other) {
+    initFrom(other.begin(), other.byteSize());
+}
+
+PodVectorBase& PodVectorBase::operator=(const PodVectorBase& other) {
+    initFrom(other.begin(), other.byteSize());
+    return *this;
+}
+
+PodVectorBase::~PodVectorBase() {
+    if (mBegin) {
+        // Sanity.
+        ::memset(mBegin, 0xee, byteSize());
+        ::free(mBegin);
+        mBegin = NULL;
+        mEnd = NULL;
+        mLimit = NULL;
+    }
+}
+
+void PodVectorBase::initFrom(const void* from, size_t fromLen) {
+    if (!fromLen || !from) {
+        mBegin = NULL;
+        mEnd = NULL;
+        mLimit = NULL;
+    } else {
+        mBegin = static_cast<char*>(::malloc(fromLen));
+        mEnd = mLimit = mBegin + fromLen;
+        ::memcpy(mBegin, from, fromLen);
+    }
+}
+
+void PodVectorBase::assignFrom(const PodVectorBase& other) {
+    resize(other.byteSize(), 1U);
+    ::memmove(begin(), other.begin(), byteSize());
+}
+
+void PodVectorBase::resize(size_t newSize, size_t itemSize) {
+    const size_t kMaxSize = maxItemCapacity(itemSize);
+    size_t oldCapacity = itemCapacity(itemSize);
+    const size_t kMinCapacity = 256 / itemSize;
+
+    if (newSize < oldCapacity) {
+        // Only shrink if the new size is really small.
+        if (newSize < oldCapacity / 2 && oldCapacity > kMinCapacity) {
+            reserve(newSize, itemSize);
+        }
+    } else if (newSize > oldCapacity) {
+        size_t newCapacity = oldCapacity;
+        while (newCapacity < newSize) {
+            size_t newCapacity2 = newCapacity + (newCapacity >> 2) + 8;
+            if (newCapacity2 < newCapacity || newCapacity > kMaxSize) {
+                newCapacity = kMaxSize;
+            } else {
+                newCapacity = newCapacity2;
+            }
+        }
+        reserve(newCapacity, itemSize);
+    }
+    mEnd = mBegin + newSize * itemSize;
+}
+
+void PodVectorBase::reserve(size_t newSize, size_t itemSize) {
+    if (newSize == 0) {
+        ::free(mBegin);
+        mBegin = NULL;
+        mEnd = NULL;
+        mLimit = NULL;
+        return;
+    }
+
+    size_t oldByteSize = byteSize();
+    size_t newByteCapacity = newSize * itemSize;
+    char* newBegin = static_cast<char*>(::realloc(mBegin, newByteCapacity));
+    mBegin = newBegin;
+    mEnd = newBegin + oldByteSize;
+#if USE_MALLOC_USABLE_SIZE
+    size_t usableSize = malloc_usable_size(mBegin);
+    if (usableSize > newByteCapacity) {
+        newByteCapacity = usableSize - (usableSize % itemSize);
+    }
+#endif
+    mLimit = newBegin + newByteCapacity;
+    // Sanity.
+    if (newByteCapacity > oldByteSize) {
+        ::memset(mBegin + oldByteSize, 0, newByteCapacity - oldByteSize);
+    }
+}
+
+void PodVectorBase::removeAt(size_t itemPos, size_t itemSize) {
+    size_t count = itemCount(itemSize);
+    if (itemPos < count) {
+        size_t  pos = itemPos * itemSize;
+        ::memmove(mBegin + pos,
+                  mBegin + pos + itemSize,
+                  byteSize() - pos - itemSize);
+        resize(count - 1U, itemSize);
+    }
+}
+
+void* PodVectorBase::insertAt(size_t itemPos, size_t itemSize) {
+    size_t count = this->itemCount(itemSize);
+    resize(count + 1, itemSize);
+    size_t pos = itemPos * itemSize;
+    if (itemPos < count) {
+        ::memmove(mBegin + pos + itemSize,
+                  mBegin + pos,
+                  count * itemSize - pos);
+        // Sanity to avoid copying pointers and other bad stuff.
+        ::memset(mBegin + pos, 0, itemSize);
+    }
+    return mBegin + pos;
+}
+
+void PodVectorBase::swapAll(PodVectorBase* other) {
+    swapPointers(&mBegin, &other->mBegin);
+    swapPointers(&mEnd, &other->mEnd);
+    swapPointers(&mLimit, &other->mLimit);
+}
+
+}  // namespace emugl