/*
* 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.
*/
package android.database;
import dalvik.system.CloseGuard;
import android.content.res.Resources;
import android.database.sqlite.SQLiteClosable;
import android.database.sqlite.SQLiteException;
import android.os.Binder;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.Process;
import android.util.Log;
import android.util.SparseIntArray;
import android.util.LongSparseArray;
/**
* A buffer containing multiple cursor rows.
* <p>
* A {@link CursorWindow} is read-write when initially created and used locally.
* When sent to a remote process (by writing it to a {@link Parcel}), the remote process
* receives a read-only view of the cursor window. Typically the cursor window
* will be allocated by the producer, filled with data, and then sent to the
* consumer for reading.
* </p>
*/
public class CursorWindow extends SQLiteClosable implements Parcelable {
private static final String STATS_TAG = "CursorWindowStats";
// This static member will be evaluated when first used.
private static int sCursorWindowSize = -1;
/**
* The native CursorWindow object pointer. (FOR INTERNAL USE ONLY)
* @hide
*/
public long mWindowPtr;
private int mStartPos;
private final String mName;
private final CloseGuard mCloseGuard = CloseGuard.get();
private static native long nativeCreate(String name, int cursorWindowSize);
private static native long nativeCreateFromParcel(Parcel parcel);
private static native void nativeDispose(long windowPtr);
private static native void nativeWriteToParcel(long windowPtr, Parcel parcel);
private static native void nativeClear(long windowPtr);
private static native int nativeGetNumRows(long windowPtr);
private static native boolean nativeSetNumColumns(long windowPtr, int columnNum);
private static native boolean nativeAllocRow(long windowPtr);
private static native void nativeFreeLastRow(long windowPtr);
private static native int nativeGetType(long windowPtr, int row, int column);
private static native byte[] nativeGetBlob(long windowPtr, int row, int column);
private static native String nativeGetString(long windowPtr, int row, int column);
private static native long nativeGetLong(long windowPtr, int row, int column);
private static native double nativeGetDouble(long windowPtr, int row, int column);
private static native void nativeCopyStringToBuffer(long windowPtr, int row, int column,
CharArrayBuffer buffer);
private static native boolean nativePutBlob(long windowPtr, byte[] value, int row, int column);
private static native boolean nativePutString(long windowPtr, String value, int row, int column);
private static native boolean nativePutLong(long windowPtr, long value, int row, int column);
private static native boolean nativePutDouble(long windowPtr, double value, int row, int column);
private static native boolean nativePutNull(long windowPtr, int row, int column);
private static native String nativeGetName(long windowPtr);
/**
* Creates a new empty cursor window and gives it a name.
* <p>
* The cursor initially has no rows or columns. Call {@link #setNumColumns(int)} to
* set the number of columns before adding any rows to the cursor.
* </p>
*
* @param name The name of the cursor window, or null if none.
*/
public CursorWindow(String name) {
mStartPos = 0;
mName = name != null && name.length() != 0 ? name : "<unnamed>";
if (sCursorWindowSize < 0) {
/** The cursor window size. resource xml file specifies the value in kB.
* convert it to bytes here by multiplying with 1024.
*/
sCursorWindowSize = Resources.getSystem().getInteger(
com.android.internal.R.integer.config_cursorWindowSize) * 1024;
}
mWindowPtr = nativeCreate(mName, sCursorWindowSize);
if (mWindowPtr == 0) {
throw new CursorWindowAllocationException("Cursor window allocation of " +
(sCursorWindowSize / 1024) + " kb failed. " + printStats());
}
mCloseGuard.open("close");
recordNewWindow(Binder.getCallingPid(), mWindowPtr);
}
/**
* Creates a new empty cursor window.
* <p>
* The cursor initially has no rows or columns. Call {@link #setNumColumns(int)} to
* set the number of columns before adding any rows to the cursor.
* </p>
*
* @param localWindow True if this window will be used in this process only,
* false if it might be sent to another processes. This argument is ignored.
*
* @deprecated There is no longer a distinction between local and remote
* cursor windows. Use the {@link #CursorWindow(String)} constructor instead.
*/
@Deprecated
public CursorWindow(boolean localWindow) {
this((String)null);
}
private CursorWindow(Parcel source) {
mStartPos = source.readInt();
mWindowPtr = nativeCreateFromParcel(source);
if (mWindowPtr == 0) {
throw new CursorWindowAllocationException("Cursor window could not be "
+ "created from binder.");
}
mName = nativeGetName(mWindowPtr);
mCloseGuard.open("close");
}
@Override
protected void finalize() throws Throwable {
try {
if (mCloseGuard != null) {
mCloseGuard.warnIfOpen();
}
dispose();
} finally {
super.finalize();
}
}
private void dispose() {
if (mCloseGuard != null) {
mCloseGuard.close();
}
if (mWindowPtr != 0) {
recordClosingOfWindow(mWindowPtr);
nativeDispose(mWindowPtr);
mWindowPtr = 0;
}
}
/**
* Gets the name of this cursor window, never null.
* @hide
*/
public String getName() {
return mName;
}
/**
* Clears out the existing contents of the window, making it safe to reuse
* for new data.
* <p>
* The start position ({@link #getStartPosition()}), number of rows ({@link #getNumRows()}),
* and number of columns in the cursor are all reset to zero.
* </p>
*/
public void clear() {
acquireReference();
try {
mStartPos = 0;
nativeClear(mWindowPtr);
} finally {
releaseReference();
}
}
/**
* Gets the start position of this cursor window.
* <p>
* The start position is the zero-based index of the first row that this window contains
* relative to the entire result set of the {@link Cursor}.
* </p>
*
* @return The zero-based start position.
*/
public int getStartPosition() {
return mStartPos;
}
/**
* Sets the start position of this cursor window.
* <p>
* The start position is the zero-based index of the first row that this window contains
* relative to the entire result set of the {@link Cursor}.
* </p>
*
* @param pos The new zero-based start position.
*/
public void setStartPosition(int pos) {
mStartPos = pos;
}
/**
* Gets the number of rows in this window.
*
* @return The number of rows in this cursor window.
*/
public int getNumRows() {
acquireReference();
try {
return nativeGetNumRows(mWindowPtr);
} finally {
releaseReference();
}
}
/**
* Sets the number of columns in this window.
* <p>
* This method must be called before any rows are added to the window, otherwise
* it will fail to set the number of columns if it differs from the current number
* of columns.
* </p>
*
* @param columnNum The new number of columns.
* @return True if successful.
*/
public boolean setNumColumns(int columnNum) {
acquireReference();
try {
return nativeSetNumColumns(mWindowPtr, columnNum);
} finally {
releaseReference();
}
}
/**
* Allocates a new row at the end of this cursor window.
*
* @return True if successful, false if the cursor window is out of memory.
*/
public boolean allocRow(){
acquireReference();
try {
return nativeAllocRow(mWindowPtr);
} finally {
releaseReference();
}
}
/**
* Frees the last row in this cursor window.
*/
public void freeLastRow(){
acquireReference();
try {
nativeFreeLastRow(mWindowPtr);
} finally {
releaseReference();
}
}
/**
* Returns true if the field at the specified row and column index
* has type {@link Cursor#FIELD_TYPE_NULL}.
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return True if the field has type {@link Cursor#FIELD_TYPE_NULL}.
* @deprecated Use {@link #getType(int, int)} instead.
*/
@Deprecated
public boolean isNull(int row, int column) {
return getType(row, column) == Cursor.FIELD_TYPE_NULL;
}
/**
* Returns true if the field at the specified row and column index
* has type {@link Cursor#FIELD_TYPE_BLOB} or {@link Cursor#FIELD_TYPE_NULL}.
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return True if the field has type {@link Cursor#FIELD_TYPE_BLOB} or
* {@link Cursor#FIELD_TYPE_NULL}.
* @deprecated Use {@link #getType(int, int)} instead.
*/
@Deprecated
public boolean isBlob(int row, int column) {
int type = getType(row, column);
return type == Cursor.FIELD_TYPE_BLOB || type == Cursor.FIELD_TYPE_NULL;
}
/**
* Returns true if the field at the specified row and column index
* has type {@link Cursor#FIELD_TYPE_INTEGER}.
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return True if the field has type {@link Cursor#FIELD_TYPE_INTEGER}.
* @deprecated Use {@link #getType(int, int)} instead.
*/
@Deprecated
public boolean isLong(int row, int column) {
return getType(row, column) == Cursor.FIELD_TYPE_INTEGER;
}
/**
* Returns true if the field at the specified row and column index
* has type {@link Cursor#FIELD_TYPE_FLOAT}.
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return True if the field has type {@link Cursor#FIELD_TYPE_FLOAT}.
* @deprecated Use {@link #getType(int, int)} instead.
*/
@Deprecated
public boolean isFloat(int row, int column) {
return getType(row, column) == Cursor.FIELD_TYPE_FLOAT;
}
/**
* Returns true if the field at the specified row and column index
* has type {@link Cursor#FIELD_TYPE_STRING} or {@link Cursor#FIELD_TYPE_NULL}.
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return True if the field has type {@link Cursor#FIELD_TYPE_STRING}
* or {@link Cursor#FIELD_TYPE_NULL}.
* @deprecated Use {@link #getType(int, int)} instead.
*/
@Deprecated
public boolean isString(int row, int column) {
int type = getType(row, column);
return type == Cursor.FIELD_TYPE_STRING || type == Cursor.FIELD_TYPE_NULL;
}
/**
* Returns the type of the field at the specified row and column index.
* <p>
* The returned field types are:
* <ul>
* <li>{@link Cursor#FIELD_TYPE_NULL}</li>
* <li>{@link Cursor#FIELD_TYPE_INTEGER}</li>
* <li>{@link Cursor#FIELD_TYPE_FLOAT}</li>
* <li>{@link Cursor#FIELD_TYPE_STRING}</li>
* <li>{@link Cursor#FIELD_TYPE_BLOB}</li>
* </ul>
* </p>
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return The field type.
*/
public int getType(int row, int column) {
acquireReference();
try {
return nativeGetType(mWindowPtr, row - mStartPos, column);
} finally {
releaseReference();
}
}
/**
* Gets the value of the field at the specified row and column index as a byte array.
* <p>
* The result is determined as follows:
* <ul>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_NULL}, then the result
* is <code>null</code>.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_BLOB}, then the result
* is the blob value.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_STRING}, then the result
* is the array of bytes that make up the internal representation of the
* string value.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_INTEGER} or
* {@link Cursor#FIELD_TYPE_FLOAT}, then a {@link SQLiteException} is thrown.</li>
* </ul>
* </p>
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return The value of the field as a byte array.
*/
public byte[] getBlob(int row, int column) {
acquireReference();
try {
return nativeGetBlob(mWindowPtr, row - mStartPos, column);
} finally {
releaseReference();
}
}
/**
* Gets the value of the field at the specified row and column index as a string.
* <p>
* The result is determined as follows:
* <ul>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_NULL}, then the result
* is <code>null</code>.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_STRING}, then the result
* is the string value.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_INTEGER}, then the result
* is a string representation of the integer in decimal, obtained by formatting the
* value with the <code>printf</code> family of functions using
* format specifier <code>%lld</code>.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_FLOAT}, then the result
* is a string representation of the floating-point value in decimal, obtained by
* formatting the value with the <code>printf</code> family of functions using
* format specifier <code>%g</code>.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_BLOB}, then a
* {@link SQLiteException} is thrown.</li>
* </ul>
* </p>
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return The value of the field as a string.
*/
public String getString(int row, int column) {
acquireReference();
try {
return nativeGetString(mWindowPtr, row - mStartPos, column);
} finally {
releaseReference();
}
}
/**
* Copies the text of the field at the specified row and column index into
* a {@link CharArrayBuffer}.
* <p>
* The buffer is populated as follows:
* <ul>
* <li>If the buffer is too small for the value to be copied, then it is
* automatically resized.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_NULL}, then the buffer
* is set to an empty string.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_STRING}, then the buffer
* is set to the contents of the string.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_INTEGER}, then the buffer
* is set to a string representation of the integer in decimal, obtained by formatting the
* value with the <code>printf</code> family of functions using
* format specifier <code>%lld</code>.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_FLOAT}, then the buffer is
* set to a string representation of the floating-point value in decimal, obtained by
* formatting the value with the <code>printf</code> family of functions using
* format specifier <code>%g</code>.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_BLOB}, then a
* {@link SQLiteException} is thrown.</li>
* </ul>
* </p>
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @param buffer The {@link CharArrayBuffer} to hold the string. It is automatically
* resized if the requested string is larger than the buffer's current capacity.
*/
public void copyStringToBuffer(int row, int column, CharArrayBuffer buffer) {
if (buffer == null) {
throw new IllegalArgumentException("CharArrayBuffer should not be null");
}
acquireReference();
try {
nativeCopyStringToBuffer(mWindowPtr, row - mStartPos, column, buffer);
} finally {
releaseReference();
}
}
/**
* Gets the value of the field at the specified row and column index as a <code>long</code>.
* <p>
* The result is determined as follows:
* <ul>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_NULL}, then the result
* is <code>0L</code>.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_STRING}, then the result
* is the value obtained by parsing the string value with <code>strtoll</code>.
* <li>If the field is of type {@link Cursor#FIELD_TYPE_INTEGER}, then the result
* is the <code>long</code> value.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_FLOAT}, then the result
* is the floating-point value converted to a <code>long</code>.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_BLOB}, then a
* {@link SQLiteException} is thrown.</li>
* </ul>
* </p>
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return The value of the field as a <code>long</code>.
*/
public long getLong(int row, int column) {
acquireReference();
try {
return nativeGetLong(mWindowPtr, row - mStartPos, column);
} finally {
releaseReference();
}
}
/**
* Gets the value of the field at the specified row and column index as a
* <code>double</code>.
* <p>
* The result is determined as follows:
* <ul>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_NULL}, then the result
* is <code>0.0</code>.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_STRING}, then the result
* is the value obtained by parsing the string value with <code>strtod</code>.
* <li>If the field is of type {@link Cursor#FIELD_TYPE_INTEGER}, then the result
* is the integer value converted to a <code>double</code>.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_FLOAT}, then the result
* is the <code>double</code> value.</li>
* <li>If the field is of type {@link Cursor#FIELD_TYPE_BLOB}, then a
* {@link SQLiteException} is thrown.</li>
* </ul>
* </p>
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return The value of the field as a <code>double</code>.
*/
public double getDouble(int row, int column) {
acquireReference();
try {
return nativeGetDouble(mWindowPtr, row - mStartPos, column);
} finally {
releaseReference();
}
}
/**
* Gets the value of the field at the specified row and column index as a
* <code>short</code>.
* <p>
* The result is determined by invoking {@link #getLong} and converting the
* result to <code>short</code>.
* </p>
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return The value of the field as a <code>short</code>.
*/
public short getShort(int row, int column) {
return (short) getLong(row, column);
}
/**
* Gets the value of the field at the specified row and column index as an
* <code>int</code>.
* <p>
* The result is determined by invoking {@link #getLong} and converting the
* result to <code>int</code>.
* </p>
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return The value of the field as an <code>int</code>.
*/
public int getInt(int row, int column) {
return (int) getLong(row, column);
}
/**
* Gets the value of the field at the specified row and column index as a
* <code>float</code>.
* <p>
* The result is determined by invoking {@link #getDouble} and converting the
* result to <code>float</code>.
* </p>
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return The value of the field as an <code>float</code>.
*/
public float getFloat(int row, int column) {
return (float) getDouble(row, column);
}
/**
* Copies a byte array into the field at the specified row and column index.
*
* @param value The value to store.
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return True if successful.
*/
public boolean putBlob(byte[] value, int row, int column) {
acquireReference();
try {
return nativePutBlob(mWindowPtr, value, row - mStartPos, column);
} finally {
releaseReference();
}
}
/**
* Copies a string into the field at the specified row and column index.
*
* @param value The value to store.
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return True if successful.
*/
public boolean putString(String value, int row, int column) {
acquireReference();
try {
return nativePutString(mWindowPtr, value, row - mStartPos, column);
} finally {
releaseReference();
}
}
/**
* Puts a long integer into the field at the specified row and column index.
*
* @param value The value to store.
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return True if successful.
*/
public boolean putLong(long value, int row, int column) {
acquireReference();
try {
return nativePutLong(mWindowPtr, value, row - mStartPos, column);
} finally {
releaseReference();
}
}
/**
* Puts a double-precision floating point value into the field at the
* specified row and column index.
*
* @param value The value to store.
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return True if successful.
*/
public boolean putDouble(double value, int row, int column) {
acquireReference();
try {
return nativePutDouble(mWindowPtr, value, row - mStartPos, column);
} finally {
releaseReference();
}
}
/**
* Puts a null value into the field at the specified row and column index.
*
* @param row The zero-based row index.
* @param column The zero-based column index.
* @return True if successful.
*/
public boolean putNull(int row, int column) {
acquireReference();
try {
return nativePutNull(mWindowPtr, row - mStartPos, column);
} finally {
releaseReference();
}
}
public static final Parcelable.Creator<CursorWindow> CREATOR
= new Parcelable.Creator<CursorWindow>() {
public CursorWindow createFromParcel(Parcel source) {
return new CursorWindow(source);
}
public CursorWindow[] newArray(int size) {
return new CursorWindow[size];
}
};
public static CursorWindow newFromParcel(Parcel p) {
return CREATOR.createFromParcel(p);
}
public int describeContents() {
return 0;
}
public void writeToParcel(Parcel dest, int flags) {
acquireReference();
try {
dest.writeInt(mStartPos);
nativeWriteToParcel(mWindowPtr, dest);
} finally {
releaseReference();
}
if ((flags & Parcelable.PARCELABLE_WRITE_RETURN_VALUE) != 0) {
releaseReference();
}
}
@Override
protected void onAllReferencesReleased() {
dispose();
}
private static final LongSparseArray<Integer> sWindowToPidMap = new LongSparseArray<Integer>();
private void recordNewWindow(int pid, long window) {
synchronized (sWindowToPidMap) {
sWindowToPidMap.put(window, pid);
if (Log.isLoggable(STATS_TAG, Log.VERBOSE)) {
Log.i(STATS_TAG, "Created a new Cursor. " + printStats());
}
}
}
private void recordClosingOfWindow(long window) {
synchronized (sWindowToPidMap) {
if (sWindowToPidMap.size() == 0) {
// this means we are not in the ContentProvider.
return;
}
sWindowToPidMap.delete(window);
}
}
private String printStats() {
StringBuilder buff = new StringBuilder();
int myPid = Process.myPid();
int total = 0;
SparseIntArray pidCounts = new SparseIntArray();
synchronized (sWindowToPidMap) {
int size = sWindowToPidMap.size();
if (size == 0) {
// this means we are not in the ContentProvider.
return "";
}
for (int indx = 0; indx < size; indx++) {
int pid = sWindowToPidMap.valueAt(indx);
int value = pidCounts.get(pid);
pidCounts.put(pid, ++value);
}
}
int numPids = pidCounts.size();
for (int i = 0; i < numPids;i++) {
buff.append(" (# cursors opened by ");
int pid = pidCounts.keyAt(i);
if (pid == myPid) {
buff.append("this proc=");
} else {
buff.append("pid " + pid + "=");
}
int num = pidCounts.get(pid);
buff.append(num + ")");
total += num;
}
// limit the returned string size to 1000
String s = (buff.length() > 980) ? buff.substring(0, 980) : buff.toString();
return "# Open Cursors=" + total + s;
}
@Override
public String toString() {
return getName() + " {" + Long.toHexString(mWindowPtr) + "}";
}
}
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