filehashRDS-class: Filehash RDS Class

Description

An implementation of filehash databases using diretories and separate files

Usage

# S4 method for filehashRDS,character
dbInsert(db, key, value, safe = TRUE, ...)
# S4 method for filehashRDS,character
dbFetch(db, key, ...)
# S4 method for filehashRDS,character
dbMultiFetch(db, key, ...)
# S4 method for filehashRDS,character
dbExists(db, key, ...)
# S4 method for filehashRDS
dbList(db, ...)
# S4 method for filehashRDS,character
dbDelete(db, key, ...)
# S4 method for filehashRDS
dbUnlink(db, ...)

Arguments

db: a filehashRDS object
key: character, the name of an R object
value: an R object
safe: Should the operation be done safely?
...: arguments passed to other methods

Methods (by generic)

dbInsert(db = filehashRDS, key = character): Insert an R object into a filehashRDS database
dbFetch(db = filehashRDS, key = character): Retrieve a value from a filehashRDS database
dbMultiFetch(db = filehashRDS, key = character): Retrieve multiple objects from a filehashRDS database
dbExists(db = filehashRDS, key = character): Determine if a key exists in a filehashRDS database
dbList(filehashRDS): Return a character vector of all key stored in a database
dbDelete(db = filehashRDS, key = character): Delete a key and its corresponding object from a filehashRDS database
dbUnlink(filehashRDS): Delete an entire filehashRDS database

Slots

dir: Directory where files are stored (filehashRDS only)

Details

When safe = TRUE in dbInsert, objects are written to a temp file before replacing any existing objects. This way, if the operation is interrupted, the original data are not corrupted.

For dbMultiFetch, key is a character vector of keys.