Flat file cache management subsystem. More...

#include "playlist.h"
#include "cache-file.h"
#include <dirent.h>
#include <errno.h>
#include <stdio.h>
#include <sys/file.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <string.h>

Data Structures
struct	mi_data_buffer
	struct type used to reduce memory usage More...

Macros
#define	CACHE_VERS 12
#define	CACHE_NF 15
#define	CA_OK 0
#define	CA_FATAL 10
#define	CA_MISSARG 20
#define	CA_CREATE 30
#define	CA_LOCKED 40
#define	ISDOT(x) ( (x)[0] == '.' && (!(x)[1] \|\| ((x)[1] == '.' && !(x)[2])) )
	test for "." and ".." dir entries.
#define	BLANKSTR(x) ( !(x) ? "#" : (x) )
	if char *x is NULL, print a printable ascii char (white space would be trashed by fscanf alas)
#define	ISBLANK(x) ( ((x)[0] == '#') && ((x)[1] == '\0') )
	Detection of our "home made" encoding of NULL strings.

Functions
static void	error_handler (request_rec r, const char const caller)
	Handles error for the flat file cache subsystem.
static short	file_cache_make_dir (request_rec r, const char const dirpath)
	Creates cache subdirectories.
static void	file_cache_remove_dir (request_rec r, DIR cachedir, const char *const curdir)
	Removes cache subdirectories.
static void *	cache_file_opendir (request_rec r, mu_pack const pack, const char const filename, const char uri, unsigned long soptions)
	Checks if a directory already exists in the cache.
static mu_ent *	file_make_cache_entry (request_rec r, apr_pool_t pool, FILE const in, const char const filename)
	Fills in the information fields about a music file from the cache.
static void	cache_file_write (request_rec r, const mu_ent const p, const char *const filename)
	Creates and writes cache file information.
int	cache_file_setup (cmd_parms cmd, const char const setup_string, mu_config *const conf)

Variables
static const cache_backend	cache_backend_file

Detailed Description

Flat file cache management subsystem.

Author: Thibaut Varene

Version

Revision:: 1011

Date: 2003-2010

Warning: 'errno' seems not to be seen as volatile by the compiler, therefore we cannot do "if(mkdir(foo) && errno == EEXIST)" for instance.

Bug:: No flat file cache support for Solaris.

Warning: We do rely on success of chdir() calls.

Todo:: O P T I M I Z E ! (maybe)

Definition in file cache-file.c.

Macro Definition Documentation

#define BLANKSTR ( x ) ( !(x) ? "#" : (x) )

if char *x is NULL, print a printable ascii char (white space would be trashed by fscanf alas)

Definition at line 68 of file cache-file.c.

Referenced by cache_file_write().

#define CA_CREATE 30

Definition at line 62 of file cache-file.c.

#define CA_FATAL 10

Definition at line 60 of file cache-file.c.

Referenced by file_cache_make_dir().

#define CA_LOCKED 40

Definition at line 63 of file cache-file.c.

#define CA_MISSARG 20

Definition at line 61 of file cache-file.c.

#define CA_OK 0

Definition at line 59 of file cache-file.c.

Referenced by file_cache_make_dir().

#define CACHE_NF 15

Definition at line 57 of file cache-file.c.

Referenced by file_make_cache_entry().

#define CACHE_VERS 12

Definition at line 56 of file cache-file.c.

Referenced by cache_file_write(), and file_make_cache_entry().

#define ISBLANK ( x ) ( ((x)[0] == '#') && ((x)[1] == '\0') )

Detection of our "home made" encoding of NULL strings.

Definition at line 70 of file cache-file.c.

Referenced by file_make_cache_entry().

#define ISDOT ( x ) ( (x)[0] == '.' && (!(x)[1] || ((x)[1] == '.' && !(x)[2])) )

test for "." and ".." dir entries.

x is a char *

Definition at line 66 of file cache-file.c.

Referenced by file_cache_remove_dir().

Function Documentation

static void* cache_file_opendir	(	request_rec *	r,
		mu_pack *const	pack,
		const char *const	filename,
		const char *	uri,
		unsigned long	soptions
	)

static

Checks if a directory already exists in the cache.

This function takes advantage of the standard behaviour of the cache backend in musicindex: this function is called when the caller wants to know whether the backend handles a given directory. We always return NULL, pretending we don't, as "handling" means being able to provide a full listing straight out of cache, which we don't in this particular incarnation, but we take the opportunity to do our own cooking with our cache data, creating the directory in cache if need be, and checking for cache data sanity.

Parameters

r	Apache request_rec struct.
pack	Ignored
filename	current directory path
uri	server-side uri (unused)
soptions	Flags to use for created entries. Ignored.

Returns: NULL.

Definition at line 280 of file cache-file.c.

References mu_config::cache_setup, error_handler(), file_cache_make_dir(), file_cache_remove_dir(), musicindex_module, and unlikely.

int cache_file_setup	(	cmd_parms *	cmd,
		const char *const	setup_string,
		mu_config *const	conf
	)

Definition at line 513 of file cache-file.c.

References apr_pstrdup, mu_config::cache, cache_backend_file, mu_config::cache_setup, and mi_serror.

static void cache_file_write	(	request_rec *	r,
		const mu_ent *const	p,
		const char *const	filename
	)

static

Creates and writes cache file information.

This function creates a new cache file (for #filename), and fills it with the data contained in the mu_ent p structure.

Parameters

r	Apache request_rec struct to handle log writings.
p	A mu_ent struct containing the data to store.
filename	current filename of the file to cache.

Definition at line 451 of file cache-file.c.

References mu_ent::album, mu_ent::artist, mu_ent::bitrate, BLANKSTR, mu_config::cache_setup, CACHE_VERS, mu_ent::date, EF_FLAGSTOSAVE, error_handler(), mu_ent::filetype, mu_ent::flags, mu_ent::freq, mu_ent::genre, mu_ent::length, mu_ent::mtime, musicindex_module, mu_ent::posn, mu_ent::size, mu_ent::title, and mu_ent::track.

static void error_handler	(	request_rec *	r,
		const char *const	caller
	)

static

Handles error for the flat file cache subsystem.

This function handles various errors depending on errno's value.

Parameters

r	Apache request_rec struct to handle log writings.
caller	A string (eg. calling function name) used in messages sent.

Todo:: Many things.

Definition at line 82 of file cache-file.c.

References mi_rerror.

Referenced by cache_file_opendir(), cache_file_write(), file_cache_make_dir(), file_cache_remove_dir(), and file_make_cache_entry().

static short file_cache_make_dir	(	request_rec *	r,
		const char *const	dirpath
	)

static

Creates cache subdirectories.

This subroutine takes care of creating all requested directories and subdirectories if they don't already exist and if possible.

Warning: If dirpath begins with a "/" the function will return immediately.

Parameters

r	Apache request_rec struct to handle log writings.
dirpath	A string representing a path to create.

Returns: CA_OK on succes, CA_FATAL otherwise.

Definition at line 167 of file cache-file.c.

References CA_FATAL, CA_OK, and error_handler().

Referenced by cache_file_opendir().

static void file_cache_remove_dir	(	request_rec *	r,
		DIR *	cachedir,
		const char *const	curdir
	)

static

Removes cache subdirectories.

This subroutine takes care of removing any given directory and its content (recursively) if any, and if possible.

Parameters

r	Apache request_rec struct to handle log writings.
cachedir	A DIR stream corresponding to the directory to remove.
curdir	A string representing the absolute path of the corresponding parent directory on the "original" filesystem.

Definition at line 216 of file cache-file.c.

References apr_pstrcat, error_handler(), ISDOT, and unlikely.

Referenced by cache_file_opendir().

static mu_ent* file_make_cache_entry	(	request_rec *	r,
		apr_pool_t *	pool,
		FILE *const	in,
		const char *const	filename
	)

static

Fills in the information fields about a music file from the cache.

This function reads the tags from the cache file and fills in the struct mu_ent fields accordingly.

Warning: MUST close in file handler on success.

Parameters

r	Apache request_rec struct to handle log writings.
pool	Apache pool
in	Not used (except for closing).
filename	current filename.

Returns: When possible, struct mu_ent correctly set up, file stream closed, NULL otherwise.

Definition at line 345 of file cache-file.c.

References mu_ent::album, mi_data_buffer::album, apr_pstrdup, mu_ent::artist, mi_data_buffer::artist, mu_ent::bitrate, CACHE_NF, mu_config::cache_setup, CACHE_VERS, mu_ent::date, error_handler(), filetype, mu_ent::filetype, mu_ent::flags, mu_ent::freq, mu_ent::genre, mi_data_buffer::genre, ISBLANK, mu_ent::length, likely, mu_ent::mtime, musicindex_module, NEW_ENT, mu_ent::posn, mu_ent::size, mu_ent::title, mi_data_buffer::title, mu_ent::track, and unlikely.

Variable Documentation

const cache_backend cache_backend_file

static

Initial value:

 {
        .opendir =      cache_file_opendir,
        .readdir =      NULL,
        .closedir =     NULL,
        .make_entry =   file_make_cache_entry,
        .write =        cache_file_write,
        .prologue =     NULL,
        .epilogue =     NULL,
}

Definition at line 503 of file cache-file.c.

Referenced by cache_file_setup().

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

Function Documentation

Variable Documentation