io-file

!!! Experimental repository - do not use in production !!!

A configurable and loggable wrapper to some node:fs functionality for basic file and extended file-data handling.

install

npm install io-file

configuration

$ tree
 . 
 ├── node_modules
 │    ...
 ├── config 
 │    ...
 │    └── io-file.ini
 ...

DEFAULT_READ_OPTIONS={"encoding":"utf8"}
DEFAULT_FILE_OPTIONS={"encoding":"utf8","mode":0o664}
DEFAULT_DIR_OPTIONS={"recursive":true,"mode":0o775}
LOG_DIR=path/to/your/log/directory
LOG_TYPE=all
ERROR_HANDLING=all
DATA_DIR=path/to/your/file/data/directory
VERSIONED_TABLE_IDENTIFIERS=["someIdentifier","anotherIdentifier"]

DEFAULT_READ_OPTIONS see https://nodejs.org/docs/latest/api/fs.html#filehandlereadfileoptions for details

DEFAULT_FILE_OPTIONS see https://nodejs.org/docs/latest/api/fs.html#filehandlewritefiledata-options for details

DEFAULT_DIR_OPTIONS see https://nodejs.org/docs/latest/api/fs.html#fspromisesmkdirpath-options for details

LOG_DIR is the path to the log directory. If it does not start with / it is calculated from the project root.

LOG_TYPE can be all, console or file. Determines whether to use a log file the console.log functionality or both.

Please note that the duration logged for the reads and writes can be a lot above the duration used by the operating system. This is due to the internal processing of async code in node.

ERROR_HANDLING can be all, log, throw. Determines whether an error will be logged, thrown or both.

DATA_DIR is the path to the data directory. It is used by the table functions.

VERSIONED_TABLE_IDENTIFIERS determines if a data table should use versioning. If a table name (path) contains an identifier it is treated as versioned by the table functions.

basic functionality

doesExist(absolutePath)

Checks if a directory/file exists asynchronously. Returns a boolean.

requirePathExists(absolutePath)

Checks if a directory exists and creates it if not asynchronously. Returns the path.

makePath(absolutePath)

Creates a directory asynchronously. Returns the path.

removePath(absolutePath)

Recursively removes a directory or a file asynchronously. A second parameter can be passed to alter the behaviour. See fs.promises.rm for details.

basic file functionality

The *SingletonFile functions don't provide any atomic constraints. On concurrent writes it can destroy your files content due to indeterministic behaviour!

readSingletonFile(absoluteFilePath)

Reads from a file asynchronously. Returns a string or null if there is no such file.

writeSingletonFile(absoluteFilePath, dataString)

Writes a file with the dataString as content asynchronously. If the directory does not exist the function creates it.

removeSingletonFile(absoluteFilePath)

Removes a file asynchronously. Returns true on success and null if there is no such file.

The *BasicFile functions do provide an atomic constraint. They do so by using the fs.promises.rename functionality. Thus, if there are concurrent writes the one who finishes last wins.

readBasicFile(absoluteFilePath)

Reads from a file asynchronously. Returns a string or null if there is no such file.

writeBasicFile(absoluteFilePath, dataString)

Writes a file with the dataString as content asynchronously. If the directory does not exist the function creates it.

removeBasicFile(absoluteFilePath)

Removes a file asynchronously. Returns true on success and null if there is no such file.

appendFile(absoluteFilePath, dataString)

Appends a dataString to a files content asynchronously. If the directory/file does not exist the function creates it. It does not provide any atomic constrain. Although nodes fs.promises.appendFile function seems to be atomic at least on linux machines.

versioned file functionality

The *VersionedFile functions provide versioning of files. The versioned files are named with the current iso date an underscore and an uuid. The most recent versioned file is linked to the provided filename.

readVersionedFile(absolutePath, fileName, fileNameExtension)

Reads from a (versioned) file asynchronously. Returns a string or null if there is no such file. Tries to recover from the existing versions if the linked file is missing.

writeVersionedFile(absolutePath, fileName, fileNameExtension, dataString)

Writes a (versioned) file with the dataString as content asynchronously. If the directory does not exist the function creates it.

data functionality

calcAbsoluteTablePath(tableName)

Returns the path where the table entries are stored.

tableDataExists(tableName, id)

Checks whether there is any data stored in the table entry asynchronously.

readFromTable(tableName, id)

Returns the stored table entry or null if there is no data stored asynchronously.

writeToTable(tableName, id, data)

Writes data to a table entry asynchronously.

removeFromTable(tableName, id)

Removes a table entry asynchronously.

allTableIds(tableName)

Returns an array of all ids associated with a table entry asynchronously.

exposed inner functionality

log(callback, logAssets, fileName)

Executes the callback and returns the result. Checks the LOG_TYPE settings and logs the logAssest together with the execution time to the specified output. If an error occurs the error is handled according to the ERROR_HANDLING settings.

readOptions()

Returns the DEFAULT_READ_OPTIONS settings.

fileOptions()

Returns the DEFAULT_FILE_OPTIONS settings.

dirOptions()

Returns the DEFAULT_DIR_OPTIONS settings.