/**
* Locate a data file and open it.
*
* This function is used to open a dictionary file or a word file,
* or any associated data file (like a post process knowledge file).
*
* It works as follows. If the file name begins with a "/", then
* it's assumed to be an absolute file name and it tries to open
* that exact file.
*
* Otherwise, it looks for the file in a sequence of directories, as
* specified in the dictpath array, until it finds it.
*
* If it is still not found, it may be that the user specified a relative
* path, so it tries to open the exact file.
*
* Associated data files are looked in the *same* directory in which the
* first one was found (typically "en/4.0.dict"). The private static
* "path_found" serves as a directory path cache which records where the
* first file was found. The goal here is to avoid insanity due to
* user's fractured installs.
* If the filename argument is NULL, the function just invalidates this
* directory path cache.
*/
void * object_open(const char *filename,
void * (*opencb)(const char *, const void *),
const void * user_data)
{
static char *path_found; /* directory path cache */
char *completename = NULL;
void *fp = NULL;
char *data_dir = NULL;
const char **path = NULL;
if (NULL == filename)
{
/* Invalidate the directory path cache */
free(path_found);
path_found = NULL;
return NULL;
}
if (NULL == path_found)
{
data_dir = dictionary_get_data_dir();
#ifdef _DEBUG
prt_error("Info: data_dir=%s", (data_dir?data_dir:"NULL"));
#endif
}
/* Look for absolute filename.
* Unix: starts with leading slash.
* Windows: starts with C:\ except that the drive letter may differ.
* Note that only native windows C library uses backslashes; mingw
* seems to use forward-slash, from what I can tell.
*/
if ((filename[0] == '/')
#if defined(_WIN32) || defined(_MSC_VER) || defined(__MINGW32__)
|| ((filename[1] == ':')
&& ((filename[2] == '\\') || (filename[2] == '/')))
#endif
)
{
/* opencb() returns NULL if the file does not exist. */
fp = opencb(filename, user_data);
#ifdef _DEBUG
prt_error("Info: 1: object_open() trying %s=%d", filename, NULL!=fp);
#endif
}
else
{
/* A path list in which to search for dictionaries.
* path_found, data_dir or DEFAULTPATH may be NULL. */
const char *dictpath[] =
{
path_found,
".",
"." DIR_SEPARATOR "data",
"..",
".." DIR_SEPARATOR "data",
data_dir,
DEFAULTPATH,
};
size_t i = sizeof(dictpath)/sizeof(dictpath[0]);
for (path = dictpath; i-- > 0; path++)
{
if (NULL == *path) continue;
free(completename);
completename = join_path(*path, filename);
fp = opencb(completename, user_data);
#ifdef _DEBUG
prt_error("Info: 2: object_open() trying %s=%d", completename, NULL!=fp);
#endif
if ((NULL != fp) || (NULL != path_found)) break;
}
}
if (NULL == fp)
{
fp = opencb(filename, user_data);
#ifdef _DEBUG
prt_error("Info: 3: object_open() trying %s=%d", filename, NULL!=fp);
#endif
}
else if (NULL == path_found)
{
size_t i;
path_found = strdup((NULL != completename) ? completename : filename);
if (0 < verbosity)
prt_error("Info: Dictionary found at %s", path_found);
for (i = 0; i < 2; i++)
{
char *root = strrchr(path_found, DIR_SEPARATOR[0]);
if (NULL != root) *root = '\0';
}
#ifdef _DEBUG
prt_error("Info: object_open() path_found=%s", path_found);
#endif
}
free(data_dir);
free(completename);
return fp;
}
void * object_open(const char *filename,
void * (*opencb)(const char *, const void *),
const void * user_data)
{
/* Dictionary data directory path cache -- per-thread storage. */
static TLS char *path_found;
char *completename = NULL;
void *fp = NULL;
char *data_dir = NULL;
const char **path = NULL;
if (NULL == filename)
{
/* Invalidate the dictionary data directory path cache. */
char *pf = path_found;
path_found = NULL;
free(pf);
return NULL;
}
if (NULL == path_found)
{
data_dir = dictionary_get_data_dir();
if (verbosity_level(D_USER_FILES))
{
char cwd[MAX_PATH_NAME];
char *cwdp = getcwd(cwd, sizeof(cwd));
prt_error("Debug: Current directory: %s\n", NULL == cwdp ? "NULL": cwdp);
prt_error("Debug: Last-resort data directory: %s\n",
data_dir ? data_dir : "NULL");
}
}
/* Look for absolute filename.
* Unix: starts with leading slash.
* Windows: starts with C:\ except that the drive letter may differ. */
if ((filename[0] == '/')
#ifdef _WIN32
|| ((filename[1] == ':')
&& ((filename[2] == '\\') || (filename[2] == '/')))
|| (filename[0] == '\\') /* UNC path */
#endif /* _WIN32 */
)
{
/* opencb() returns NULL if the file does not exist. */
fp = opencb(filename, user_data);
lgdebug(D_USER_FILES, "Debug: Opening file %s%s\n", filename, NOTFOUND(fp));
}
else
{
/* A path list in which to search for dictionaries.
* path_found, data_dir or DEFAULTPATH may be NULL. */
const char *dictpath[] =
{
path_found,
".",
"." DIR_SEPARATOR "data",
"..",
".." DIR_SEPARATOR "data",
data_dir,
DEFAULTPATH,
};
size_t i = sizeof(dictpath)/sizeof(dictpath[0]);
for (path = dictpath; i-- > 0; path++)
{
if (NULL == *path) continue;
free(completename);
completename = join_path(*path, filename);
fp = opencb(completename, user_data);
lgdebug(D_USER_FILES, "Debug: Opening file %s%s\n", completename, NOTFOUND(fp));
if ((NULL != fp) || (NULL != path_found)) break;
}
}
if (NULL == fp)
{
fp = opencb(filename, user_data);
lgdebug(D_USER_FILES, "Debug: Opening file %s%s\n", filename, NOTFOUND(fp));
}
else if (NULL == path_found)
{
char *pfnd = strdup((NULL != completename) ? completename : filename);
if ((0 < verbosity) && (dict_file_open == opencb))
prt_error("Info: Dictionary found at %s\n", pfnd);
for (size_t i = 0; i < 2; i++)
{
char *root = strrchr(pfnd, DIR_SEPARATOR[0]);
if (NULL != root) *root = '\0';
}
path_found = pfnd;
}
free(data_dir);
free(completename);
return fp;
}