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LIBHAMMER(3)          DragonFly Library Functions Manual          LIBHAMMER(3)


NAME

     hammer - HAMMER file system interface


LIBRARY

     HAMMER Filesystem Userland Library (libhammer, -lhammer)


SYNOPSIS

     #include <libhammer.h>


DESCRIPTION

     The hammer library provides a set of functions which serve as an
     interface to applications that need to obtain information or perform
     maintenance operations in HAMMER(5) file systems.


INTRODUCTION

     This library is an attempt to factor out most of the code in the initial
     hammer(8) program greatly reducing its complexity and taking advantage of
     all the functionality it contained helping other programs to reuse it.

     There are several parts of the HAMMER(5) file system for which this
     library provides an API:

     *   Information facilities: The following information is gathered and
         exposed by this library:

               -   File system specific information such as size, big block
                   details, version, PFSes, snapshots, mount points.

               -   Statistical data like number of B-Tree operations, number
                   of device operations, number of undo operations.

     *   Pseudo-file systems: These are independent sub file systems within a
         HAMMER file system.  After hammer library initialisation the list of
         pseudo-file systems will be available in the libhammer_fsinfo
         structure within a TAILQ.

         Creating and deleting pseudo-file systems is not yet supported by
         this library.

     *   Snapshots: Per PFS point in time snapshots are kept in the file
         system meta-data since HAMMER version 3.  A list of snapshots is
         collected and placed within a TAILQ for each PFS.

         Creating and deleting snapshots is not yet supported by this library.


INITIALISATION

     Before any API call the library must be initialised with the
     libhammer_get_fsinfo() function.  This will perform all the operations
     needed to initialise the data structures in which the API function rely
     for the specified HAMMER file system.

     Once you are done, the special function libhammer_free_fsinfo() will
     release all the resources used by the library during its initialisation
     and usage.


SEE ALSO

     libhammer_fsinfo(3), libhammer_snapshot(3), libhammer_stats(3),
     HAMMER(5), hammer(8)


AUTHORS

     This man page was written by Antonio Huete Jimenez
     <tuxillo@quantumachine.net>.


BUGS

     Please note that, at the moment of writing this man page, the hammer
     library is incomplete.

DragonFly 5.9-DEVELOPMENT      February 19, 2015     DragonFly 5.9-DEVELOPMENT

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