package android.os;
/**
* Describes the source of some work that may be done by someone else.
* Currently the public representation of what a work source is is not
* defined; this is an opaque container.
*/
public class WorkSource implements Parcelable {
int mNum;
int[] mUids;
/**
* Internal statics to avoid object allocations in some operations.
* The WorkSource object itself is not thread safe, but we need to
* hold sTmpWorkSource lock while working with these statics.
*/
static final WorkSource sTmpWorkSource = new WorkSource(0);
/**
* For returning newbie work from a modification operation.
*/
static WorkSource sNewbWork;
/**
* For returning gone work form a modification operation.
*/
static WorkSource sGoneWork;
/**
* Create an empty work source.
*/
public WorkSource() {
mNum = 0;
}
/**
* Create a new WorkSource that is a copy of an existing one.
* If <var>orig</var> is null, an empty WorkSource is created.
*/
public WorkSource(WorkSource orig) {
if (orig == null) {
mNum = 0;
return;
}
mNum = orig.mNum;
if (orig.mUids != null) {
mUids = orig.mUids.clone();
} else {
mUids = null;
}
}
/** @hide */
public WorkSource(int uid) {
mNum = 1;
mUids = new int[] { uid, 0 };
}
WorkSource(Parcel in) {
mNum = in.readInt();
mUids = in.createIntArray();
}
/** @hide */
public int size() {
return mNum;
}
/** @hide */
public int get(int index) {
return mUids[index];
}
/**
* Clear this WorkSource to be empty.
*/
public void clear() {
mNum = 0;
}
/**
* Compare this WorkSource with another.
* @param other The WorkSource to compare against.
* @return If there is a difference, true is returned.
*/
public boolean diff(WorkSource other) {
int N = mNum;
if (N != other.mNum) {
return true;
}
final int[] uids1 = mUids;
final int[] uids2 = other.mUids;
for (int i=0; i<N; i++) {
if (uids1[i] != uids2[i]) {
return true;
}
}
return false;
}
/**
* Replace the current contents of this work source with the given
* work source. If <var>other</var> is null, the current work source
* will be made empty.
*/
public void set(WorkSource other) {
if (other == null) {
mNum = 0;
return;
}
mNum = other.mNum;
if (other.mUids != null) {
if (mUids != null && mUids.length >= mNum) {
System.arraycopy(other.mUids, 0, mUids, 0, mNum);
} else {
mUids = other.mUids.clone();
}
} else {
mUids = null;
}
}
/** @hide */
public void set(int uid) {
mNum = 1;
if (mUids == null) mUids = new int[2];
mUids[0] = uid;
}
/** @hide */
public WorkSource[] setReturningDiffs(WorkSource other) {
synchronized (sTmpWorkSource) {
sNewbWork = null;
sGoneWork = null;
updateLocked(other, true, true);
if (sNewbWork != null || sGoneWork != null) {
WorkSource[] diffs = new WorkSource[2];
diffs[0] = sNewbWork;
diffs[1] = sGoneWork;
return diffs;
}
return null;
}
}
/**
* Merge the contents of <var>other</var> WorkSource in to this one.
*
* @param other The other WorkSource whose contents are to be merged.
* @return Returns true if any new sources were added.
*/
public boolean add(WorkSource other) {
synchronized (sTmpWorkSource) {
return updateLocked(other, false, false);
}
}
/** @hide */
public WorkSource addReturningNewbs(WorkSource other) {
synchronized (sTmpWorkSource) {
sNewbWork = null;
updateLocked(other, false, true);
return sNewbWork;
}
}
/** @hide */
public boolean add(int uid) {
synchronized (sTmpWorkSource) {
sTmpWorkSource.mUids[0] = uid;
return updateLocked(sTmpWorkSource, false, false);
}
}
/** @hide */
public WorkSource addReturningNewbs(int uid) {
synchronized (sTmpWorkSource) {
sNewbWork = null;
sTmpWorkSource.mUids[0] = uid;
updateLocked(sTmpWorkSource, false, true);
return sNewbWork;
}
}
public boolean remove(WorkSource other) {
int N1 = mNum;
final int[] uids1 = mUids;
final int N2 = other.mNum;
final int[] uids2 = other.mUids;
boolean changed = false;
int i1 = 0;
for (int i2=0; i2<N2 && i1<N1; i2++) {
if (uids2[i2] == uids1[i1]) {
N1--;
if (i1 < N1) System.arraycopy(uids1, i1+1, uids1, i1, N1-i1);
}
while (i1 < N1 && uids2[i2] > uids1[i1]) {
i1++;
}
}
mNum = N1;
return changed;
}
private boolean updateLocked(WorkSource other, boolean set, boolean returnNewbs) {
int N1 = mNum;
int[] uids1 = mUids;
final int N2 = other.mNum;
final int[] uids2 = other.mUids;
boolean changed = false;
int i1 = 0;
for (int i2=0; i2<N2; i2++) {
if (i1 >= N1 || uids2[i2] < uids1[i1]) {
// Need to insert a new uid.
changed = true;
if (uids1 == null) {
uids1 = new int[4];
uids1[0] = uids2[i2];
} else if (i1 >= uids1.length) {
int[] newuids = new int[(uids1.length*3)/2];
if (i1 > 0) System.arraycopy(uids1, 0, newuids, 0, i1);
if (i1 < N1) System.arraycopy(uids1, i1, newuids, i1+1, N1-i1);
uids1 = newuids;
uids1[i1] = uids2[i2];
} else {
if (i1 < N1) System.arraycopy(uids1, i1, uids1, i1+1, N1-i1);
uids1[i1] = uids2[i2];
}
if (returnNewbs) {
if (sNewbWork == null) {
sNewbWork = new WorkSource(uids2[i2]);
} else {
sNewbWork.addLocked(uids2[i2]);
}
}
N1++;
i1++;
} else {
if (!set) {
// Skip uids that already exist or are not in 'other'.
do {
i1++;
} while (i1 < N1 && uids2[i2] >= uids1[i1]);
} else {
// Remove any uids that don't exist in 'other'.
int start = i1;
while (i1 < N1 && uids2[i2] > uids1[i1]) {
if (sGoneWork == null) {
sGoneWork = new WorkSource(uids1[i1]);
} else {
sGoneWork.addLocked(uids1[i1]);
}
i1++;
}
if (start < i1) {
System.arraycopy(uids1, i1, uids1, start, i1-start);
N1 -= i1-start;
i1 = start;
}
// If there is a matching uid, skip it.
if (i1 < N1 && uids2[i1] == uids1[i1]) {
i1++;
}
}
}
}
mNum = N1;
mUids = uids1;
return changed;
}
private void addLocked(int uid) {
if (mUids == null) {
mUids = new int[4];
mUids[0] = uid;
mNum = 1;
return;
}
if (mNum >= mUids.length) {
int[] newuids = new int[(mNum*3)/2];
System.arraycopy(mUids, 0, newuids, 0, mNum);
mUids = newuids;
}
mUids[mNum] = uid;
mNum++;
}
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeInt(mNum);
dest.writeIntArray(mUids);
}
public static final Parcelable.Creator<WorkSource> CREATOR
= new Parcelable.Creator<WorkSource>() {
public WorkSource createFromParcel(Parcel in) {
return new WorkSource(in);
}
public WorkSource[] newArray(int size) {
return new WorkSource[size];
}
};
}