public async stageBlock()

in src/blob/persistence/SqlBlobMetadataStore.ts [1427:1517]
86 lines of code
6 McCabe index (conditional complexity)

  public async stageBlock(
    context: Context,
    block: BlockModel,
    leaseAccessConditions?: Models.LeaseAccessConditions
  ): Promise<void> {
    await this.sequelize.transaction(async (t) => {
      await this.assertContainerExists(
        context,
        block.accountName,
        block.containerName,
        t
      );

      const blobFindResult = await BlobsModel.findOne({
        where: {
          accountName: block.accountName,
          containerName: block.containerName,
          blobName: block.blobName,
          snapshot: "",
          deleting: 0
        },
        transaction: t
      });

      if (blobFindResult !== null && blobFindResult !== undefined) {
        const blobModel: BlobModel = this.convertDbModelToBlobModel(
          blobFindResult
        );

        if (blobModel.isCommitted === true) {
          LeaseFactory.createLeaseState(
            new BlobLeaseAdapter(blobModel),
            context
          ).validate(new BlobWriteLeaseValidator(leaseAccessConditions));
        }

        // If the new block ID does not have same length with before uncommitted block ID, return failure.
        const existBlock = await BlocksModel.findOne({
          attributes: ["blockName"],
          where: {
            accountName: block.accountName,
            containerName: block.containerName,
            blobName: block.blobName,
            deleting: 0
          },
          order: [["id", "ASC"]],
          transaction: t
        });
        if (
          existBlock &&
          Buffer.from(
            this.getModelValue<string>(existBlock, "blockName", true),
            "base64"
          ).length !== Buffer.from(block.name, "base64").length
        ) {
          throw StorageErrorFactory.getInvalidBlobOrBlock(context.contextId);
        }
      } else {
        const newBlob = {
          deleted: false,
          accountName: block.accountName,
          containerName: block.containerName,
          name: block.blobName,
          properties: {
            creationTime: context.startTime!,
            lastModified: context.startTime!,
            etag: newEtag(),
            contentLength: 0,
            blobType: Models.BlobType.BlockBlob
          },
          snapshot: "",
          isCommitted: false
        };
        await BlobsModel.upsert(this.convertBlobModelToDbModel(newBlob), {
          transaction: t
        });
      }

      await BlocksModel.upsert(
        {
          accountName: block.accountName,
          containerName: block.containerName,
          blobName: block.blobName,
          blockName: block.name,
          size: block.size,
          persistency: this.serializeModelValue(block.persistency)
        },
        { transaction: t }
      );
    });
  }