Method commitNewFile

src/generic/key_value_filesystem.ts:1157–1206

* Commits a new file (well, a FILE or a DIRECTORY) to the file system with * the given mode. * Note: This will commit the transaction. * @param p The path to the new file. * @param type The type of the new file. * @param mode The mode to create the new file with. * @param data The

(tx: AsyncKeyValueRWTransaction, p: string, type: FileType, mode: number, data: Buffer, cb: BFSCallback<Inode>)

   * @param cb Passed an error or the Inode for the new file.
   */
  private commitNewFile(tx: AsyncKeyValueRWTransaction, p: string, type: FileType, mode: number, data: Buffer, cb: BFSCallback<Inode>): void {
    const parentDir = path.dirname(p),
      fname = path.basename(p),
      currTime = (new Date()).getTime();

    // Invariant: The root always exists.
    // If we don't check this prior to taking steps below, we will create a
    // file with name '' in root should p == '/'.
    if (p === '/') {
      return cb(ApiError.EEXIST(p));
    }

    // Let's build a pyramid of code!

    // Step 1: Get the parent directory's inode and directory listing
    this.findINodeAndDirListing(tx, parentDir, (e?: ApiError | null, parentNode?: Inode, dirListing?: {[name: string]: string}): void => {
      if (noErrorTx(e, tx, cb)) {
        if (dirListing![fname]) {
          // File already exists.
          tx.abort(() => {
            cb(ApiError.EEXIST(p));
          });
        } else {
          // Step 2: Commit data to store.
          this.addNewNode(tx, data, (e: ApiError, dataId?: string): void => {
            if (noErrorTx(e, tx, cb)) {
              // Step 3: Commit the file's inode to the store.
              const fileInode = new Inode(dataId!, data.length, mode | type, currTime, currTime, currTime);
              this.addNewNode(tx, fileInode.toBuffer(), (e: ApiError, fileInodeId?: string): void => {
                if (noErrorTx(e, tx, cb)) {
                  // Step 4: Update parent directory's listing.
                  dirListing![fname] = fileInodeId!;
                  tx.put(parentNode!.id, Buffer.from(JSON.stringify(dirListing)), true, (e: ApiError): void => {
                    if (noErrorTx(e, tx, cb)) {
                      // Step 5: Commit and return the new inode.
                      tx.commit((e?: ApiError): void => {
                        if (noErrorTx(e, tx, cb)) {
                          cb(null, fileInode);
                        }
                      });
                    }
                  });
                }
              });
            }
          });
        }
      }
    });
  }

  /**
   * Remove all traces of the given path from the file system.