Method save

tfjs-core/src/io/local_storage.ts:166–228

* Save model artifacts to browser local storage. * * See the documentation to `browserLocalStorage` for details on the saved * artifacts. * * @param modelArtifacts The model artifacts to be stored. * @returns An instance of SaveResult.

(modelArtifacts: ModelArtifacts)

   * @returns An instance of SaveResult.
   */
  async save(modelArtifacts: ModelArtifacts): Promise<SaveResult> {
    if (modelArtifacts.modelTopology instanceof ArrayBuffer) {
      throw new Error(
          'BrowserLocalStorage.save() does not support saving model topology ' +
          'in binary formats yet.');
    } else {
      const topology = JSON.stringify(modelArtifacts.modelTopology);
      const weightSpecs = JSON.stringify(modelArtifacts.weightSpecs);

      const modelArtifactsInfo: ModelArtifactsInfo =
          getModelArtifactsInfoForJSON(modelArtifacts);

      // TODO(mattsoulanille): Support saving models over 2GB that exceed
      // Chrome's ArrayBuffer size limit.
      const weightBuffer = CompositeArrayBuffer.join(modelArtifacts.weightData);

      try {
        this.LS.setItem(this.keys.info, JSON.stringify(modelArtifactsInfo));
        this.LS.setItem(this.keys.topology, topology);
        this.LS.setItem(this.keys.weightSpecs, weightSpecs);
        this.LS.setItem(
            this.keys.weightData,
            arrayBufferToBase64String(weightBuffer));

        // Note that JSON.stringify doesn't write out keys that have undefined
        // values, so for some keys, we set undefined instead of a null-ish
        // value.
        const metadata: Required<ModelMetadata> = {
          format: modelArtifacts.format,
          generatedBy: modelArtifacts.generatedBy,
          convertedBy: modelArtifacts.convertedBy,
          signature: modelArtifacts.signature != null ?
              modelArtifacts.signature :
              undefined,
          userDefinedMetadata: modelArtifacts.userDefinedMetadata != null ?
              modelArtifacts.userDefinedMetadata :
              undefined,
          modelInitializer: modelArtifacts.modelInitializer != null ?
              modelArtifacts.modelInitializer :
              undefined,
          initializerSignature: modelArtifacts.initializerSignature != null ?
              modelArtifacts.initializerSignature :
              undefined,
          trainingConfig: modelArtifacts.trainingConfig != null ?
              modelArtifacts.trainingConfig :
              undefined
        };
        this.LS.setItem(this.keys.modelMetadata, JSON.stringify(metadata));

        return {modelArtifactsInfo};
      } catch (err) {
        // If saving failed, clean up all items saved so far.
        removeItems(this.keys);

        throw new Error(
            `Failed to save model '${this.modelPath}' to local storage: ` +
            `size quota being exceeded is a possible cause of this failure: ` +
            `modelTopologyBytes=${modelArtifactsInfo.modelTopologyBytes}, ` +