src/com/android/providers/media/MediaThumbRequest.java - platform/packages/providers/MediaProvider - Git at Google

 /*
  * Copyright (C) 2009 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 com.android.providers.media;

 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.OutputStream;
 import java.util.Comparator;
 import java.util.Random;

 import android.content.ContentResolver;
 import android.content.ContentUris;
 import android.content.ContentValues;
 import android.database.Cursor;
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import android.media.MiniThumbFile;
 import android.media.ThumbnailUtils;
 import android.net.Uri;
 import android.os.Binder;
 import android.os.ParcelFileDescriptor;
 import android.provider.BaseColumns;
 import android.provider.MediaStore.Images;
 import android.provider.MediaStore.Video;
 import android.provider.MediaStore.MediaColumns;
 import android.provider.MediaStore.Images.ImageColumns;
 import android.util.Log;

 /**
  * Instances of this class are created and put in a queue to be executed sequentially to see if
  * it needs to (re)generate the thumbnails.
  */
 class MediaThumbRequest {
     private static final String TAG = "MediaThumbRequest";
     static final int PRIORITY_LOW = 20;
     static final int PRIORITY_NORMAL = 10;
     static final int PRIORITY_HIGH = 5;
     static final int PRIORITY_CRITICAL = 0;
     static enum State {WAIT, DONE, CANCEL}
     private static final String[] THUMB_PROJECTION = new String[] {
         BaseColumns._ID // 0
     };

     ContentResolver mCr;
     String mPath;
     long mRequestTime = System.currentTimeMillis();
     int mCallingPid = Binder.getCallingPid();
     long mGroupId;
     int mPriority;
     Uri mUri;
     Uri mThumbUri;
     String mOrigColumnName;
     boolean mIsVideo;
     long mOrigId;
     State mState = State.WAIT;
     long mMagic;

     private static final Random sRandom = new Random();

     static Comparator<MediaThumbRequest> getComparator() {
         return new Comparator<MediaThumbRequest>() {
             public int compare(MediaThumbRequest r1, MediaThumbRequest r2) {
                 if (r1.mPriority != r2.mPriority) {
                     return r1.mPriority < r2.mPriority ? -1 : 1;
                 }
                 return r1.mRequestTime == r2.mRequestTime ? 0 :
                         r1.mRequestTime < r2.mRequestTime ? -1 : 1;
             }
         };
     }

     MediaThumbRequest(ContentResolver cr, String path, Uri uri, int priority, long magic) {
         mCr = cr;
         mPath = path;
         mPriority = priority;
         mMagic = magic;
         mUri = uri;
         mIsVideo = "video".equals(uri.getPathSegments().get(1));
         mOrigId = ContentUris.parseId(uri);
         mThumbUri = mIsVideo
                 ? Video.Thumbnails.EXTERNAL_CONTENT_URI
                 : Images.Thumbnails.EXTERNAL_CONTENT_URI;
         mOrigColumnName = mIsVideo
                 ? Video.Thumbnails.VIDEO_ID
                 : Images.Thumbnails.IMAGE_ID;
         // Only requests from Thumbnail API has this group_id parameter. In other cases,
         // mGroupId will always be zero and can't be canceled due to pid mismatch.
         String groupIdParam = uri.getQueryParameter("group_id");
         if (groupIdParam != null) {
             mGroupId = Long.parseLong(groupIdParam);
         }
     }

     Uri updateDatabase(Bitmap thumbnail) {
         Cursor c = mCr.query(mThumbUri, THUMB_PROJECTION,
                 mOrigColumnName+ " = " + mOrigId, null, null);
         if (c == null) return null;
         try {
             if (c.moveToFirst()) {
                 return ContentUris.withAppendedId(mThumbUri, c.getLong(0));
             }
         } finally {
             if (c != null) c.close();
         }

         ContentValues values = new ContentValues(4);
         values.put(Images.Thumbnails.KIND, Images.Thumbnails.MINI_KIND);
         values.put(mOrigColumnName, mOrigId);
         values.put(Images.Thumbnails.WIDTH, thumbnail.getWidth());
         values.put(Images.Thumbnails.HEIGHT, thumbnail.getHeight());
         try {
             return mCr.insert(mThumbUri, values);
         } catch (Exception ex) {
             Log.w(TAG, ex);
             return null;
         }
     }

     /**
      * Check if the corresponding thumbnail and mini-thumb have been created
      * for the given uri. This method creates both of them if they do not
      * exist yet or have been changed since last check. After thumbnails are
      * created, MINI_KIND thumbnail is stored in JPEG file and MICRO_KIND
      * thumbnail is stored in a random access file (MiniThumbFile).
      *
      * @throws IOException
      */
     void execute() throws IOException {
         MiniThumbFile miniThumbFile = MiniThumbFile.instance(mUri);
         long magic = mMagic;
         if (magic != 0) {
             long fileMagic = miniThumbFile.getMagic(mOrigId);
             if (fileMagic == magic) {
                 Cursor c = null;
                 ParcelFileDescriptor pfd = null;
                 // Clear calling identity as we may be handling an IPC.
                 final long identity = Binder.clearCallingIdentity();
                 try {
                     c = mCr.query(mThumbUri, THUMB_PROJECTION,
                             mOrigColumnName + " = " + mOrigId, null, null);
                     if (c != null && c.moveToFirst()) {
                         pfd = mCr.openFileDescriptor(
                                 mThumbUri.buildUpon().appendPath(c.getString(0)).build(), "r");
                     }
                 } catch (IOException ex) {
                     // MINI_THUMBNAIL not exists, ignore the exception and generate one.
                 } finally {
                     Binder.restoreCallingIdentity(identity);
                     if (c != null) c.close();
                     if (pfd != null) {
                         pfd.close();
                         return;
                     }
                 }
             }
         }

         // If we can't retrieve the thumbnail, first check if there is one
         // embedded in the EXIF data. If not, or it's not big enough,
         // decompress the full size image.
         Bitmap bitmap = null;

         if (mPath != null) {
             if (mIsVideo) {
                 bitmap = ThumbnailUtils.createVideoThumbnail(mPath,
                         Video.Thumbnails.MINI_KIND);
             } else {
                 bitmap = ThumbnailUtils.createImageThumbnail(mPath,
                         Images.Thumbnails.MINI_KIND);
             }
             if (bitmap == null) {
                 Log.w(TAG, "Can't create mini thumbnail for " + mPath);
                 return;
             }

             Uri uri = updateDatabase(bitmap);
             if (uri != null) {
                 OutputStream thumbOut = mCr.openOutputStream(uri);
                 bitmap.compress(Bitmap.CompressFormat.JPEG, 85, thumbOut);
                 thumbOut.close();
             }
         }

         bitmap = ThumbnailUtils.extractThumbnail(bitmap,
                         ThumbnailUtils.TARGET_SIZE_MICRO_THUMBNAIL,
                         ThumbnailUtils.TARGET_SIZE_MICRO_THUMBNAIL,
                         ThumbnailUtils.OPTIONS_RECYCLE_INPUT);

         if (bitmap != null) {
             ByteArrayOutputStream miniOutStream = new ByteArrayOutputStream();
             bitmap.compress(Bitmap.CompressFormat.JPEG, 75, miniOutStream);
             bitmap.recycle();
             byte [] data = null;

             try {
                 miniOutStream.close();
                 data = miniOutStream.toByteArray();
             } catch (java.io.IOException ex) {
                 Log.e(TAG, "got exception ex " + ex);
             }

             // We may consider retire this proprietary format, after all it's size is only
             // 128 x 128 at most, which is still reasonable to be stored in database.
             // Gallery application can use the MINI_THUMB_MAGIC value to determine if it's
             // time to query and fetch by using Cursor.getBlob
             if (data != null) {
                 // make a new magic number since things are out of sync
                 do {
                     magic = sRandom.nextLong();
                 } while (magic == 0);

                 miniThumbFile.saveMiniThumbToFile(data, mOrigId, magic);
                 ContentValues values = new ContentValues();
                 // both video/images table use the same column name "mini_thumb_magic"
                 values.put(ImageColumns.MINI_THUMB_MAGIC, magic);
                 try {
                     mCr.update(mUri, values, null, null);
                     mMagic = magic;
                 } catch (java.lang.IllegalStateException ex) {
                     Log.e(TAG, "got exception while updating database " + ex);
                 }
             }
         } else {
             Log.w(TAG, "can't create bitmap for thumbnail.");
         }
         miniThumbFile.deactivate();
     }
 }
	/*
	* Copyright (C) 2009 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 com.android.providers.media;

	import java.io.ByteArrayOutputStream;
	import java.io.IOException;
	import java.io.OutputStream;
	import java.util.Comparator;
	import java.util.Random;

	import android.content.ContentResolver;
	import android.content.ContentUris;
	import android.content.ContentValues;
	import android.database.Cursor;
	import android.graphics.Bitmap;
	import android.graphics.BitmapFactory;
	import android.media.MiniThumbFile;
	import android.media.ThumbnailUtils;
	import android.net.Uri;
	import android.os.Binder;
	import android.os.ParcelFileDescriptor;
	import android.provider.BaseColumns;
	import android.provider.MediaStore.Images;
	import android.provider.MediaStore.Video;
	import android.provider.MediaStore.MediaColumns;
	import android.provider.MediaStore.Images.ImageColumns;
	import android.util.Log;

	/**
	* Instances of this class are created and put in a queue to be executed sequentially to see if
	* it needs to (re)generate the thumbnails.
	*/
	class MediaThumbRequest {
	private static final String TAG = "MediaThumbRequest";
	static final int PRIORITY_LOW = 20;
	static final int PRIORITY_NORMAL = 10;
	static final int PRIORITY_HIGH = 5;
	static final int PRIORITY_CRITICAL = 0;
	static enum State {WAIT, DONE, CANCEL}
	private static final String[] THUMB_PROJECTION = new String[] {
	BaseColumns._ID // 0
	};

	ContentResolver mCr;
	String mPath;
	long mRequestTime = System.currentTimeMillis();
	int mCallingPid = Binder.getCallingPid();
	long mGroupId;
	int mPriority;
	Uri mUri;
	Uri mThumbUri;
	String mOrigColumnName;
	boolean mIsVideo;
	long mOrigId;
	State mState = State.WAIT;
	long mMagic;

	private static final Random sRandom = new Random();

	static Comparator<MediaThumbRequest> getComparator() {
	return new Comparator<MediaThumbRequest>() {
	public int compare(MediaThumbRequest r1, MediaThumbRequest r2) {
	if (r1.mPriority != r2.mPriority) {
	return r1.mPriority < r2.mPriority ? -1 : 1;
	}
	return r1.mRequestTime == r2.mRequestTime ? 0 :
	r1.mRequestTime < r2.mRequestTime ? -1 : 1;
	}
	};
	}

	MediaThumbRequest(ContentResolver cr, String path, Uri uri, int priority, long magic) {
	mCr = cr;
	mPath = path;
	mPriority = priority;
	mMagic = magic;
	mUri = uri;
	mIsVideo = "video".equals(uri.getPathSegments().get(1));
	mOrigId = ContentUris.parseId(uri);
	mThumbUri = mIsVideo
	? Video.Thumbnails.EXTERNAL_CONTENT_URI
	: Images.Thumbnails.EXTERNAL_CONTENT_URI;
	mOrigColumnName = mIsVideo
	? Video.Thumbnails.VIDEO_ID
	: Images.Thumbnails.IMAGE_ID;
	// Only requests from Thumbnail API has this group_id parameter. In other cases,
	// mGroupId will always be zero and can't be canceled due to pid mismatch.
	String groupIdParam = uri.getQueryParameter("group_id");
	if (groupIdParam != null) {
	mGroupId = Long.parseLong(groupIdParam);
	}
	}

	Uri updateDatabase(Bitmap thumbnail) {
	Cursor c = mCr.query(mThumbUri, THUMB_PROJECTION,
	mOrigColumnName+ " = " + mOrigId, null, null);
	if (c == null) return null;
	try {
	if (c.moveToFirst()) {
	return ContentUris.withAppendedId(mThumbUri, c.getLong(0));
	}
	} finally {
	if (c != null) c.close();
	}

	ContentValues values = new ContentValues(4);
	values.put(Images.Thumbnails.KIND, Images.Thumbnails.MINI_KIND);
	values.put(mOrigColumnName, mOrigId);
	values.put(Images.Thumbnails.WIDTH, thumbnail.getWidth());
	values.put(Images.Thumbnails.HEIGHT, thumbnail.getHeight());
	try {
	return mCr.insert(mThumbUri, values);
	} catch (Exception ex) {
	Log.w(TAG, ex);
	return null;
	}
	}

	/**
	* Check if the corresponding thumbnail and mini-thumb have been created
	* for the given uri. This method creates both of them if they do not
	* exist yet or have been changed since last check. After thumbnails are
	* created, MINI_KIND thumbnail is stored in JPEG file and MICRO_KIND
	* thumbnail is stored in a random access file (MiniThumbFile).
	*
	* @throws IOException
	*/
	void execute() throws IOException {
	MiniThumbFile miniThumbFile = MiniThumbFile.instance(mUri);
	long magic = mMagic;
	if (magic != 0) {
	long fileMagic = miniThumbFile.getMagic(mOrigId);
	if (fileMagic == magic) {
	Cursor c = null;
	ParcelFileDescriptor pfd = null;
	// Clear calling identity as we may be handling an IPC.
	final long identity = Binder.clearCallingIdentity();
	try {
	c = mCr.query(mThumbUri, THUMB_PROJECTION,
	mOrigColumnName + " = " + mOrigId, null, null);
	if (c != null && c.moveToFirst()) {
	pfd = mCr.openFileDescriptor(
	mThumbUri.buildUpon().appendPath(c.getString(0)).build(), "r");
	}
	} catch (IOException ex) {
	// MINI_THUMBNAIL not exists, ignore the exception and generate one.
	} finally {
	Binder.restoreCallingIdentity(identity);
	if (c != null) c.close();
	if (pfd != null) {
	pfd.close();
	return;
	}
	}
	}
	}

	// If we can't retrieve the thumbnail, first check if there is one
	// embedded in the EXIF data. If not, or it's not big enough,
	// decompress the full size image.
	Bitmap bitmap = null;

	if (mPath != null) {
	if (mIsVideo) {
	bitmap = ThumbnailUtils.createVideoThumbnail(mPath,
	Video.Thumbnails.MINI_KIND);
	} else {
	bitmap = ThumbnailUtils.createImageThumbnail(mPath,
	Images.Thumbnails.MINI_KIND);
	}
	if (bitmap == null) {
	Log.w(TAG, "Can't create mini thumbnail for " + mPath);
	return;
	}

	Uri uri = updateDatabase(bitmap);
	if (uri != null) {
	OutputStream thumbOut = mCr.openOutputStream(uri);
	bitmap.compress(Bitmap.CompressFormat.JPEG, 85, thumbOut);
	thumbOut.close();
	}
	}

	bitmap = ThumbnailUtils.extractThumbnail(bitmap,
	ThumbnailUtils.TARGET_SIZE_MICRO_THUMBNAIL,
	ThumbnailUtils.TARGET_SIZE_MICRO_THUMBNAIL,
	ThumbnailUtils.OPTIONS_RECYCLE_INPUT);

	if (bitmap != null) {
	ByteArrayOutputStream miniOutStream = new ByteArrayOutputStream();
	bitmap.compress(Bitmap.CompressFormat.JPEG, 75, miniOutStream);
	bitmap.recycle();
	byte [] data = null;

	try {
	miniOutStream.close();
	data = miniOutStream.toByteArray();
	} catch (java.io.IOException ex) {
	Log.e(TAG, "got exception ex " + ex);
	}

	// We may consider retire this proprietary format, after all it's size is only
	// 128 x 128 at most, which is still reasonable to be stored in database.
	// Gallery application can use the MINI_THUMB_MAGIC value to determine if it's
	// time to query and fetch by using Cursor.getBlob
	if (data != null) {
	// make a new magic number since things are out of sync
	do {
	magic = sRandom.nextLong();
	} while (magic == 0);

	miniThumbFile.saveMiniThumbToFile(data, mOrigId, magic);
	ContentValues values = new ContentValues();
	// both video/images table use the same column name "mini_thumb_magic"
	values.put(ImageColumns.MINI_THUMB_MAGIC, magic);
	try {
	mCr.update(mUri, values, null, null);
	mMagic = magic;
	} catch (java.lang.IllegalStateException ex) {
	Log.e(TAG, "got exception while updating database " + ex);
	}
	}
	} else {
	Log.w(TAG, "can't create bitmap for thumbnail.");
	}
	miniThumbFile.deactivate();
	}
	}