ujs-safefile 0.1.0

API

readFile

Read a file synchronously from a file system.

readFile (filename)

data = readFile (filename)

writeFile

Write a file synchronously to a file system.

writeFile (filename, data)

writeFile (filename, data)

safeReadFile

Read a file synchronously from a file system, inspecting the file system state and performing recovery processing if needed.

safeReadFile (filename)

data = safeReadFile (filename)

safeWriteFile

Write data to a file synchronously, using a recoverable set of steps. Should the write processing fail to complete, auto-recovery can perform the steps required to bring the file content back to a stable state.

safeWriteFile (filename, data)

safeWriteFile (filename, data)

safeGetState

Get the current state of the set of files representing the current file system contents. Returns one of,

• SAFE_NORMAL, normal state, base and backup files only present

• SAFE_RECOVERABLE, partial write condition that is automatically recoverable the next time a read, write or recover function is called

• SAFE_INTERVENE, last write failed before the data being written reached a recoverable state. Manual intervention is required if recovery of the last write is required, otherwise auto-recovery will recover to the prior stable state.

safeGetState (filename)

state = safeGetState (filename)

safeRecover

Initiate the auto-recovery process. This follows the same steps as safeReadFile follows, but can be called independently.

safeRecover (filename)

safeRecover (file)

SafeFileError

SafeFileError (code, message)

Constants for the error codes,

• NO_ERROR

• INVALID_NAME

• DOES_NOT_EXIST

• IS_NOT_A_FILE

• READ_ERROR

• WRITE_ERROR

• SAFE_NORMAL

• SAFE_RECOVERABLE

• SAFE_INTERVENE

Installation

The program can be installed using pip, with the command,

pip install ujs-safefile

License

MIT