jodd-proxetta/src/main/java/jodd/asm7/MethodWriter.java
private void putFrame() {
    final int numLocal = currentFrame[1];
    final int numStack = currentFrame[2];
    if (symbolTable.getMajorVersion() < Opcodes.V1_6) {
      // Generate a StackMap attribute entry, which are always uncompressed.
      stackMapTableEntries.putShort(currentFrame[0]).putShort(numLocal);
      putAbstractTypes(3, 3 + numLocal);
      stackMapTableEntries.putShort(numStack);
      putAbstractTypes(3 + numLocal, 3 + numLocal + numStack);
      return;
    }
    final int offsetDelta =
        stackMapTableNumberOfEntries == 0
            ? currentFrame[0]
            : currentFrame[0] - previousFrame[0] - 1;
    final int previousNumlocal = previousFrame[1];
    final int numLocalDelta = numLocal - previousNumlocal;
    int type = Frame.FULL_FRAME;
    if (numStack == 0) {
      switch (numLocalDelta) {
        case -3:
        case -2:
        case -1:
          type = Frame.CHOP_FRAME;
          break;
        case 0:
          type = offsetDelta < 64 ? Frame.SAME_FRAME : Frame.SAME_FRAME_EXTENDED;
          break;
        case 1:
        case 2:
        case 3:
          type = Frame.APPEND_FRAME;
          break;
        default:
          // Keep the FULL_FRAME type.
          break;
      }
    } else if (numLocalDelta == 0 && numStack == 1) {
      type =
          offsetDelta < 63
              ? Frame.SAME_LOCALS_1_STACK_ITEM_FRAME
              : Frame.SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED;
    }
    if (type != Frame.FULL_FRAME) {
      // Verify if locals are the same as in the previous frame.
      int frameIndex = 3;
      for (int i = 0; i < previousNumlocal && i < numLocal; i++) {
        if (currentFrame[frameIndex] != previousFrame[frameIndex]) {
          type = Frame.FULL_FRAME;
          break;
        }
        frameIndex++;
      }
    }
    switch (type) {
      case Frame.SAME_FRAME:
        stackMapTableEntries.putByte(offsetDelta);
        break;
      case Frame.SAME_LOCALS_1_STACK_ITEM_FRAME:
        stackMapTableEntries.putByte(Frame.SAME_LOCALS_1_STACK_ITEM_FRAME + offsetDelta);
        putAbstractTypes(3 + numLocal, 4 + numLocal);
        break;
      case Frame.SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED:
        stackMapTableEntries
            .putByte(Frame.SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED)
            .putShort(offsetDelta);
        putAbstractTypes(3 + numLocal, 4 + numLocal);
        break;
      case Frame.SAME_FRAME_EXTENDED:
        stackMapTableEntries.putByte(Frame.SAME_FRAME_EXTENDED).putShort(offsetDelta);
        break;
      case Frame.CHOP_FRAME:
        stackMapTableEntries
            .putByte(Frame.SAME_FRAME_EXTENDED + numLocalDelta)
            .putShort(offsetDelta);
        break;
      case Frame.APPEND_FRAME:
        stackMapTableEntries
            .putByte(Frame.SAME_FRAME_EXTENDED + numLocalDelta)
            .putShort(offsetDelta);
        putAbstractTypes(3 + previousNumlocal, 3 + numLocal);
        break;
      case Frame.FULL_FRAME:
      default:
        stackMapTableEntries.putByte(Frame.FULL_FRAME).putShort(offsetDelta).putShort(numLocal);
        putAbstractTypes(3, 3 + numLocal);
        stackMapTableEntries.putShort(numStack);
        putAbstractTypes(3 + numLocal, 3 + numLocal + numStack);
        break;
    }
  }
private void putFrame() {
    final int numLocal = currentFrame[1];
    final int numStack = currentFrame[2];
    if (symbolTable.getMajorVersion() < Opcodes.V1_6) {
      // Generate a StackMap attribute entry, which are always uncompressed.
      stackMapTableEntries.putShort(currentFrame[0]).putShort(numLocal);
      putAbstractTypes(3, 3 + numLocal);
      stackMapTableEntries.putShort(numStack);
      putAbstractTypes(3 + numLocal, 3 + numLocal + numStack);
      return;
    }
    final int offsetDelta =
        stackMapTableNumberOfEntries == 0
            ? currentFrame[0]
            : currentFrame[0] - previousFrame[0] - 1;
    final int previousNumlocal = previousFrame[1];
    final int numLocalDelta = numLocal - previousNumlocal;
    int type = Frame.FULL_FRAME;
    if (numStack == 0) {
      switch (numLocalDelta) {
        case -3:
        case -2:
        case -1:
          type = Frame.CHOP_FRAME;
          break;
        case 0:
          type = offsetDelta < 64 ? Frame.SAME_FRAME : Frame.SAME_FRAME_EXTENDED;
          break;
        case 1:
        case 2:
        case 3:
          type = Frame.APPEND_FRAME;
          break;
        default:
          // Keep the FULL_FRAME type.
          break;
      }
    } else if (numLocalDelta == 0 && numStack == 1) {
      type =
          offsetDelta < 63
              ? Frame.SAME_LOCALS_1_STACK_ITEM_FRAME
              : Frame.SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED;
    }
    if (type != Frame.FULL_FRAME) {
      // Verify if locals are the same as in the previous frame.
      int frameIndex = 3;
      for (int i = 0; i < previousNumlocal && i < numLocal; i++) {
        if (currentFrame[frameIndex] != previousFrame[frameIndex]) {
          type = Frame.FULL_FRAME;
          break;
        }
        frameIndex++;
      }
    }
    switch (type) {
      case Frame.SAME_FRAME:
        stackMapTableEntries.putByte(offsetDelta);
        break;
      case Frame.SAME_LOCALS_1_STACK_ITEM_FRAME:
        stackMapTableEntries.putByte(Frame.SAME_LOCALS_1_STACK_ITEM_FRAME + offsetDelta);
        putAbstractTypes(3 + numLocal, 4 + numLocal);
        break;
      case Frame.SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED:
        stackMapTableEntries
            .putByte(Frame.SAME_LOCALS_1_STACK_ITEM_FRAME_EXTENDED)
            .putShort(offsetDelta);
        putAbstractTypes(3 + numLocal, 4 + numLocal);
        break;
      case Frame.SAME_FRAME_EXTENDED:
        stackMapTableEntries.putByte(Frame.SAME_FRAME_EXTENDED).putShort(offsetDelta);
        break;
      case Frame.CHOP_FRAME:
        stackMapTableEntries
            .putByte(Frame.SAME_FRAME_EXTENDED + numLocalDelta)
            .putShort(offsetDelta);
        break;
      case Frame.APPEND_FRAME:
        stackMapTableEntries
            .putByte(Frame.SAME_FRAME_EXTENDED + numLocalDelta)
            .putShort(offsetDelta);
        putAbstractTypes(3 + previousNumlocal, 3 + numLocal);
        break;
      case Frame.FULL_FRAME:
      default:
        stackMapTableEntries.putByte(Frame.FULL_FRAME).putShort(offsetDelta).putShort(numLocal);
        putAbstractTypes(3, 3 + numLocal);
        stackMapTableEntries.putShort(numStack);
        putAbstractTypes(3 + numLocal, 3 + numLocal + numStack);
        break;
    }
  }
Compresses and writes {@link #currentFrame} in a new StackMapTable entry.