1 files changed, 193 insertions, 0 deletions
diff --git a/include/androidfw/CursorWindow.h b/include/androidfw/CursorWindow.h
new file mode 100644
index 0000000..8a2979a
--- /dev/null
+++ b/include/androidfw/CursorWindow.h
@@ -0,0 +1,193 @@
+/*
+ * Copyright (C) 2006 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 _ANDROID__DATABASE_WINDOW_H
+#define _ANDROID__DATABASE_WINDOW_H
+
+#include <cutils/log.h>
+#include <stddef.h>
+#include <stdint.h>
+
+#include <binder/Parcel.h>
+#include <utils/String8.h>
+
+#if LOG_NDEBUG
+
+#define IF_LOG_WINDOW() if (false)
+#define LOG_WINDOW(...)
+
+#else
+
+#define IF_LOG_WINDOW() IF_ALOG(LOG_DEBUG, "CursorWindow")
+#define LOG_WINDOW(...) ALOG(LOG_DEBUG, "CursorWindow", __VA_ARGS__)
+
+#endif
+
+namespace android {
+
+/**
+ * This class stores a set of rows from a database in a buffer. The begining of the
+ * window has first chunk of RowSlots, which are offsets to the row directory, followed by
+ * an offset to the next chunk in a linked-list of additional chunk of RowSlots in case
+ * the pre-allocated chunk isn't big enough to refer to all rows. Each row directory has a
+ * FieldSlot per column, which has the size, offset, and type of the data for that field.
+ * Note that the data types come from sqlite3.h.
+ *
+ * Strings are stored in UTF-8.
+ */
+class CursorWindow {
+    CursorWindow(const String8& name, int ashmemFd,
+            void* data, size_t size, bool readOnly);
+
+public:
+    /* Field types. */
+    enum {
+        FIELD_TYPE_NULL = 0,
+        FIELD_TYPE_INTEGER = 1,
+        FIELD_TYPE_FLOAT = 2,
+        FIELD_TYPE_STRING = 3,
+        FIELD_TYPE_BLOB = 4,
+    };
+
+    /* Opaque type that describes a field slot. */
+    struct FieldSlot {
+    private:
+        int32_t type;
+        union {
+            double d;
+            int64_t l;
+            struct {
+                uint32_t offset;
+                uint32_t size;
+            } buffer;
+        } data;
+
+        friend class CursorWindow;
+    } __attribute((packed));
+
+    ~CursorWindow();
+
+    static status_t create(const String8& name, size_t size, CursorWindow** outCursorWindow);
+    static status_t createFromParcel(Parcel* parcel, CursorWindow** outCursorWindow);
+
+    status_t writeToParcel(Parcel* parcel);
+
+    inline String8 name() { return mName; }
+    inline size_t size() { return mSize; }
+    inline size_t freeSpace() { return mSize - mHeader->freeOffset; }
+    inline uint32_t getNumRows() { return mHeader->numRows; }
+    inline uint32_t getNumColumns() { return mHeader->numColumns; }
+
+    status_t clear();
+    status_t setNumColumns(uint32_t numColumns);
+
+    /**
+     * Allocate a row slot and its directory.
+     * The row is initialized will null entries for each field.
+     */
+    status_t allocRow();
+    status_t freeLastRow();
+
+    status_t putBlob(uint32_t row, uint32_t column, const void* value, size_t size);
+    status_t putString(uint32_t row, uint32_t column, const char* value, size_t sizeIncludingNull);
+    status_t putLong(uint32_t row, uint32_t column, int64_t value);
+    status_t putDouble(uint32_t row, uint32_t column, double value);
+    status_t putNull(uint32_t row, uint32_t column);
+
+    /**
+     * Gets the field slot at the specified row and column.
+     * Returns null if the requested row or column is not in the window.
+     */
+    FieldSlot* getFieldSlot(uint32_t row, uint32_t column);
+
+    inline int32_t getFieldSlotType(FieldSlot* fieldSlot) {
+        return fieldSlot->type;
+    }
+
+    inline int64_t getFieldSlotValueLong(FieldSlot* fieldSlot) {
+        return fieldSlot->data.l;
+    }
+
+    inline double getFieldSlotValueDouble(FieldSlot* fieldSlot) {
+        return fieldSlot->data.d;
+    }
+
+    inline const char* getFieldSlotValueString(FieldSlot* fieldSlot,
+            size_t* outSizeIncludingNull) {
+        *outSizeIncludingNull = fieldSlot->data.buffer.size;
+        return static_cast<char*>(offsetToPtr(fieldSlot->data.buffer.offset));
+    }
+
+    inline const void* getFieldSlotValueBlob(FieldSlot* fieldSlot, size_t* outSize) {
+        *outSize = fieldSlot->data.buffer.size;
+        return offsetToPtr(fieldSlot->data.buffer.offset);
+    }
+
+private:
+    static const size_t ROW_SLOT_CHUNK_NUM_ROWS = 100;
+
+    struct Header {
+        // Offset of the lowest unused byte in the window.
+        uint32_t freeOffset;
+
+        // Offset of the first row slot chunk.
+        uint32_t firstChunkOffset;
+
+        uint32_t numRows;
+        uint32_t numColumns;
+    };
+
+    struct RowSlot {
+        uint32_t offset;
+    };
+
+    struct RowSlotChunk {
+        RowSlot slots[ROW_SLOT_CHUNK_NUM_ROWS];
+        uint32_t nextChunkOffset;
+    };
+
+    String8 mName;
+    int mAshmemFd;
+    void* mData;
+    size_t mSize;
+    bool mReadOnly;
+    Header* mHeader;
+
+    inline void* offsetToPtr(uint32_t offset) {
+        return static_cast<uint8_t*>(mData) + offset;
+    }
+
+    inline uint32_t offsetFromPtr(void* ptr) {
+        return static_cast<uint8_t*>(ptr) - static_cast<uint8_t*>(mData);
+    }
+
+    /**
+     * Allocate a portion of the window. Returns the offset
+     * of the allocation, or 0 if there isn't enough space.
+     * If aligned is true, the allocation gets 4 byte alignment.
+     */
+    uint32_t alloc(size_t size, bool aligned = false);
+
+    RowSlot* getRowSlot(uint32_t row);
+    RowSlot* allocRowSlot();
+
+    status_t putBlobOrString(uint32_t row, uint32_t column,
+            const void* value, size_t size, int32_t type);
+};
+
+}; // namespace android
+
+#endif