fortran-tcdb

A collection of ISO C binding interfaces to the
Tokyo Cabinet key-value database for Fortran

1. At the moment, only hash databases are supported.

The interfaces are split across several modules:

• tchdb.f90: File-based hash database API.
• tcmdb.f90: On-memory hash database API.
• tclist.f90: Array List API.
• tcmisc.f90: Miscellaneous utilities API (date & time, MD5).
• tcutil.f90: Includes hack to access Tokyo Cabinet version number.

Tested with Tokyo Cabinet 1.4.48 on FreeBSD 12 with GNU Fortran 9, but should be
compatible to other Unix-like operating systems and Fortran 2008 compilers.

String Arguments

In some cases, convenience routines are used to add c_null_char to string
arguments automatically. Performance is therefore slightly decreased, as an
additional function call is necessary. To avoid these wrappers, affected
interfaces are exposed directly, with a trailing underscore in their name, but
null termination must be handled manually:

! Calling the wrapper function that does null termination for us:
err = tc_hdb_put2(hdb, 'foo', 'bar')
! Calling the interface directly:
err = tc_hdb_put2_(hdb, 'foo' // c_null_char, 'bar' // c_null_char)

Build

At first, install Tokyo Cabinet. On FreeBSD, run:

# pkg install databases/tokyocabinet

Development headers may be required on Linux. Then, compile the static library
libfortran-tcdb.a with:

$ make static

Make sure that PREFIX points to the correct path. Link Tokyo Cabinet with
libfortran-tcdb.a and -ltokyocabinet -lz -lbz2 -lrt -lpthread -lm -lc.

Example

! example.f90
program main
    use, intrinsic :: iso_c_binding, only: c_ptr
    use :: tchdb
    implicit none
    type(c_ptr)                   :: hdb
    character(len=:), allocatable :: value
    logical                       :: err
    hdb = tc_hdb_new()
    err = tc_hdb_open(hdb, 'casket.tch', ior(HDB_OWRITER, HDB_OCREAT))
    err = tc_hdb_put2(hdb, 'foo', 'bar')
    value = tc_hdb_get2(hdb, 'foo')
    print '(2a)', 'value: ', value
    err = tc_hdb_close(hdb)
    call tc_hdb_del(hdb)
end program main

Compile and run the example with:

$ gfortran -I/usr/local/include/ -L/usr/local/lib/ -o example example.f90 libfortran-tcdb.a -ltokyocabinet
$ ./example

Further Examples

Additional examples can be found in examples/:

• hdb opens a hash database and does read/write operations.
• mdb creates an on-memory hash database to store strings.
• list pushes strings to an array list.
• tcv prints the Tokyo Cabinet version number (in case you really need this info …).

Build them with:

$ make examples

Coverage

Array List API

On-Memory Hash Database API

Hash Database API

Basic Utilities API

Miscellaneous Utilities API

Licence

ISC