All files / json-crdt-patch/codec/binary Encoder.ts

98.13% Statements 158/161
92.3% Branches 36/39
100% Functions 7/7
98.02% Lines 149/152

Press n or j to go to the next uncovered block, b, p or k for the previous block.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247193x   193x 193x 193x           193x 193x             193x 193x                   7455x 7455x 7455x 7455x 7455x 7455x 7455x 7455x 3x 7455x 7455x       7455x 7455x 7455x 32879x       56690x 56690x 56690x 56690x 31440x   25250x 25250x         10813x 10813x       5820x 5820x 3305x   2515x 2515x   5820x 5820x 5820x       32879x 32879x 32879x   2613x 2613x 2613x 4x 4x   2609x 2609x   2613x     784x 784x     3957x 3957x     2x 2x     3250x 3250x     754x 754x     2454x 2454x     1560x 1560x 1560x 1560x 1560x     4482x 4482x 4482x 4482x 4310x   172x 172x   4482x 4482x 11285x 11285x 11285x   4482x     1x 1x 1x 1x 1x         1x 1x 1x 1x 1x   1x     5671x 5671x 5671x 5671x 5671x 5671x 5671x 5671x 5671x 149x 149x   5671x     2094x 2094x 2094x 2094x 639x   1455x 1455x   2094x 2094x 2094x 2094x     1747x 1747x 1747x 1747x 1586x   161x 161x   1747x 1747x 4618x 1747x     12x 12x 12x 12x 12x 12x     3008x 3008x 3008x 3008x 2638x   370x 370x   3008x 10813x 3008x     490x 490x 490x 160x   330x 330x   490x                
import * as operations from '../../operations';
import {JsonCrdtPatchOpcodeOverlay} from '../../constants';
import {CrdtWriter} from '../../util/binary/CrdtWriter';
import {type ITimespanStruct, type ITimestampStruct, Timestamp} from '../../clock';
import {CborEncoder} from '@jsonjoy.com/json-pack/lib/cbor/CborEncoder';
import type {JsonCrdtPatchOperation, Patch} from '../../Patch';
 
/**
 * JSON CRDT Patch "binary" codec encoder.
 */
export class Encoder extends CborEncoder<CrdtWriter> {
  private patchSid: number = 0;
 
  /**
   * Creates a new encoder instance.
   *
   * @param writer An optional custom implementation of CRDT writer.
   */
  constructor(public readonly writer: CrdtWriter = new CrdtWriter()) {
    super(writer);
  }
 
  /**
   * Encodes a JSON CRDT Patch into a {@link Uint8Array} blob.
   *
   * @param patch A JSON CRDT Patch to encode.
   * @returns A {@link Uint8Array} blob containing the encoded JSON CRDT Patch.
   */
  public encode(patch: Patch): Uint8Array {
    this.writer.reset();
    const id = patch.getId()!;
    const sid = (this.patchSid = id.sid);
    const writer = this.writer;
    writer.vu57(sid);
    writer.vu57(id.time);
    const meta = patch.meta;
    if (meta === undefined) this.writeUndef();
    else this.writeArr([meta]);
    this.encodeOperations(patch);
    return writer.flush();
  }
 
  protected encodeOperations(patch: Patch): void {
    const ops = patch.ops;
    const length = ops.length;
    this.writer.vu57(length);
    for (let i = 0; i < length; i++) this.encodeOperation(ops[i]);
  }
 
  protected encodeId(id: ITimestampStruct) {
    const sessionId = id.sid;
    const time = id.time;
    const writer = this.writer;
    if (sessionId === this.patchSid) {
      writer.b1vu56(0, time);
    } else {
      writer.b1vu56(1, time);
      writer.vu57(sessionId);
    }
  }
 
  protected encodeTss(span: ITimespanStruct): void {
    this.encodeId(span);
    this.writer.vu57(span.span);
  }
 
  private writeInsStr(length: number, obj: ITimestampStruct, ref: ITimestampStruct, str: string): number {
    const writer = this.writer;
    if (length <= 0b111) {
      writer.u8(JsonCrdtPatchOpcodeOverlay.ins_str + length);
    } else {
      writer.u8(JsonCrdtPatchOpcodeOverlay.ins_str);
      writer.vu57(length);
    }
    this.encodeId(obj);
    this.encodeId(ref);
    return writer.utf8(str);
  }
 
  protected encodeOperation(op: JsonCrdtPatchOperation): void {
    const writer = this.writer;
    const constr = op.constructor;
    switch (constr) {
      case operations.NewConOp: {
        const operation = <operations.NewConOp>op;
        const val = operation.val;
        if (val instanceof Timestamp) {
          writer.u8(JsonCrdtPatchOpcodeOverlay.new_con + 1);
          this.encodeId(val);
        } else {
          writer.u8(JsonCrdtPatchOpcodeOverlay.new_con);
          this.writeAny(val);
        }
        break;
      }
      case operations.NewValOp: {
        writer.u8(JsonCrdtPatchOpcodeOverlay.new_val);
        break;
      }
      case operations.NewObjOp: {
        writer.u8(JsonCrdtPatchOpcodeOverlay.new_obj);
        break;
      }
      case operations.NewVecOp: {
        writer.u8(JsonCrdtPatchOpcodeOverlay.new_vec);
        break;
      }
      case operations.NewStrOp: {
        writer.u8(JsonCrdtPatchOpcodeOverlay.new_str);
        break;
      }
      case operations.NewBinOp: {
        writer.u8(JsonCrdtPatchOpcodeOverlay.new_bin);
        break;
      }
      case operations.NewArrOp: {
        writer.u8(JsonCrdtPatchOpcodeOverlay.new_arr);
        break;
      }
      case operations.InsValOp: {
        const operation = <operations.InsValOp>op;
        writer.u8(JsonCrdtPatchOpcodeOverlay.ins_val);
        this.encodeId(operation.obj);
        this.encodeId(operation.val);
        break;
      }
      case operations.InsObjOp: {
        const operation = <operations.InsObjOp>op;
        const data = operation.data;
        const length = data.length;
        if (length <= 0b111) {
          writer.u8(JsonCrdtPatchOpcodeOverlay.ins_obj + length);
        } else {
          writer.u8(JsonCrdtPatchOpcodeOverlay.ins_obj);
          writer.vu57(length);
        }
        this.encodeId(operation.obj);
        for (let i = 0; i < length; i++) {
          const tuple = data[i];
          this.writeStr(tuple[0]);
          this.encodeId(tuple[1]);
        }
        break;
      }
      case operations.InsVecOp: {
        const operation = <operations.InsVecOp>op;
        const data = operation.data;
        const length = data.length;
        if (length <= 0b111) {
          writer.u8(JsonCrdtPatchOpcodeOverlay.ins_vec + length);
        } else E{
          writer.u8(JsonCrdtPatchOpcodeOverlay.ins_vec);
          writer.vu57(length);
        }
        this.encodeId(operation.obj);
        for (let i = 0; i < length; i++) {
          const tuple = data[i];
          writer.u8(tuple[0]);
          this.encodeId(tuple[1]);
        }
        break;
      }
      case operations.InsStrOp: {
        const operation = <operations.InsStrOp>op;
        const obj = operation.obj;
        const ref = operation.ref;
        const str = operation.data;
        const len1 = str.length;
        writer.ensureCapacity(24 + len1 * 4);
        const x = writer.x;
        const len2 = this.writeInsStr(len1, obj, ref, str);
        if (len1 !== len2) {
          writer.x = x;
          this.writeInsStr(len2, obj, ref, str);
        }
        break;
      }
      case operations.InsBinOp: {
        const operation = <operations.InsBinOp>op;
        const buf = operation.data;
        const length = buf.length;
        if (length <= 0b111) {
          writer.u8(JsonCrdtPatchOpcodeOverlay.ins_bin + length);
        } else {
          writer.u8(JsonCrdtPatchOpcodeOverlay.ins_bin);
          writer.vu57(length);
        }
        this.encodeId(operation.obj);
        this.encodeId(operation.ref);
        writer.buf(buf, length);
        break;
      }
      case operations.InsArrOp: {
        const operation = <operations.InsArrOp>op;
        const elements = operation.data;
        const length = elements.length;
        if (length <= 0b111) {
          writer.u8(JsonCrdtPatchOpcodeOverlay.ins_arr + length);
        } else {
          writer.u8(JsonCrdtPatchOpcodeOverlay.ins_arr);
          writer.vu57(length);
        }
        this.encodeId(operation.obj);
        this.encodeId(operation.ref);
        for (let i = 0; i < length; i++) this.encodeId(elements[i]);
        break;
      }
      case operations.UpdArrOp: {
        const operation = <operations.UpdArrOp>op;
        writer.u8(JsonCrdtPatchOpcodeOverlay.upd_arr);
        this.encodeId(operation.obj);
        this.encodeId(operation.ref);
        this.encodeId(operation.val);
        break;
      }
      case operations.DelOp: {
        const operation = <operations.DelOp>op;
        const what = operation.what;
        const length = what.length;
        if (length <= 0b111) {
          writer.u8(JsonCrdtPatchOpcodeOverlay.del + length);
        } else {
          writer.u8(JsonCrdtPatchOpcodeOverlay.del);
          writer.vu57(length);
        }
        this.encodeId(operation.obj);
        for (let i = 0; i < length; i++) this.encodeTss(what[i]);
        break;
      }
      case operations.NopOp: {
        const operation = <operations.NopOp>op;
        const length = operation.len;
        if (length <= 0b111) {
          writer.u8(JsonCrdtPatchOpcodeOverlay.nop + length);
        } else {
          writer.u8(JsonCrdtPatchOpcodeOverlay.nop);
          writer.vu57(length);
        }
        break;
      }
      default: {
        throw new Error('UNKNOWN_OP');
      }
    }
  }
}