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Move capabilities into a single column.

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This commit is contained in:
Greyson Parrelli
2020-10-19 17:16:40 -04:00
committed by Alan Evans
parent ead64d92a5
commit 3357475fc4
9 changed files with 276 additions and 60 deletions
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74
app/src/main/java/org/thoughtcrime/securesms/util/Bitmask.java Normal file
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@@ -0,0 +1,74 @@
package org.thoughtcrime.securesms.util;
import org.whispersystems.libsignal.util.guava.Preconditions;
import java.util.Locale;
/**
* A set of utilities to make working with Bitmasks easier.
*/
public final class Bitmask {
/**
* Reads a bitmasked boolean from a long at the requested position.
*/
public static boolean read(long value, int position) {
return read(value, position, 1) > 0;
}
/**
* Reads a bitmasked value from a long at the requested position.
*
* @param value The value your are reading state from
* @param position The position you'd like to read from
* @param flagBitSize How many bits are in each flag
* @return The value at the requested position
*/
public static long read(long value, int position, int flagBitSize) {
Preconditions.checkArgument(flagBitSize >= 0, "Must have a positive bit size! size: " + flagBitSize);
int bitsToShift = position * flagBitSize;
Preconditions.checkArgument(bitsToShift + flagBitSize <= 64 && position >= 0, String.format(Locale.US, "Your position is out of bounds! position: %d, flagBitSize: %d", position, flagBitSize));
long shifted = value >>> bitsToShift;
long mask = twoToThe(flagBitSize) - 1;
return shifted & mask;
}
/**
* Sets the value at the specified position in a single-bit bitmasked long.
*/
public static long update(long existing, int position, boolean value) {
return update(existing, position, 1, value ? 1 : 0);
}
/**
* Updates the value in a bitmasked long.
*
* @param existing The existing state of the bitmask
* @param position The position you'd like to update
* @param flagBitSize How many bits are in each flag
* @param value The value you'd like to set at the specified position
* @return The updated bitmask
*/
public static long update(long existing, int position, int flagBitSize, long value) {
Preconditions.checkArgument(flagBitSize >= 0, "Must have a positive bit size! size: " + flagBitSize);
Preconditions.checkArgument(value >= 0, "Value must be positive! value: " + value);
Preconditions.checkArgument(value < twoToThe(flagBitSize), String.format(Locale.US, "Value is larger than you can hold for the given bitsize! value: %d, flagBitSize: %d", value, flagBitSize));
int bitsToShift = position * flagBitSize;
Preconditions.checkArgument(bitsToShift + flagBitSize <= 64 && position >= 0, String.format(Locale.US, "Your position is out of bounds! position: %d, flagBitSize: %d", position, flagBitSize));
long clearMask = ~((twoToThe(flagBitSize) - 1) << bitsToShift);
long cleared = existing & clearMask;
long shiftedValue = value << bitsToShift;
return cleared | shiftedValue;
}
/** Simple method to do 2^n. Giving it a name just so it's clear what's happening. */
private static long twoToThe(long n) {
return 1 << n;
}
}

8
app/src/main/java/org/thoughtcrime/securesms/util/CursorUtil.java
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@@ -30,6 +30,14 @@ public final class CursorUtil {
return cursor.getBlob(cursor.getColumnIndexOrThrow(column));
}
public static boolean requireMaskedBoolean(@NonNull Cursor cursor, @NonNull String column, int position) {
return Bitmask.read(requireLong(cursor, column), position);
}
public static int requireMaskedInt(@NonNull Cursor cursor, @NonNull String column, int position, int flagBitSize) {
return Util.toIntExact(Bitmask.read(requireLong(cursor, column), position, flagBitSize));
}
public static Optional<String> getString(@NonNull Cursor cursor, @NonNull String column) {
if (cursor.getColumnIndex(column) < 0) {
return Optional.absent();