cache.c

UNIX环境下命令行FTP/SFTP工具源代码

/* $Id: cache.c,v 1.6 2003/07/12 10:25:41 mhe Exp $
 *
 * cache.c -- remote directory cache
 *
 * Yet Another FTP Client
 * Copyright (C) 1998-2001, Martin Hedenfalk <[e-mail]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version. See COPYING for more details.
 */

#include "syshdr.h"

#include "ftp.h"
#include "xmalloc.h"
#include "strq.h"
#include "gvars.h"

void ftp_cache_list_contents(void)
{
	listitem *li = ftp->cache->first;

	ftp_cache_flush();

	printf("Directory cache contents: (%u items)\n",
		   list_numitem(ftp->cache));

	while(li) {
		printf("%s\n", ((rdirectory *)li->data)->path);
		li = li->next;
	}
}

/* marks the directory PATH to be flushed in the
 * next call to ftp_cache_flush()
 */
void ftp_cache_flush_mark(const char *path)
{
	char *p = ftp_path_absolute(path);
	stripslash(p);

	if(list_search(ftp->dirs_to_flush, (listsearchfunc)strcmp, p) != 0)
		/* already in the flush list */
		return;

	list_additem(ftp->dirs_to_flush, p);
	ftp_trace("marked directory '%s' for flush\n", p);
}

/* marks the directory *containing* PATH to be flushed in
 * the next call to ftp_cache_flush()
 */
void ftp_cache_flush_mark_for(const char *path)
{
	char *e = base_dir_xptr(path);
	if(!e) {
		free(e);
		e = xstrdup(ftp->curdir);
	}
	ftp_cache_flush_mark(e);
	free(e);
}

static int cache_search(rdirectory *rdir, const char *arg)
{
	return strcmp(rdir->path, arg);
}

/* flushes directories marked by ftp_cache_flush_mark*()
 */
void ftp_cache_flush(void)
{
	listitem *e;
	listitem *li = ftp->dirs_to_flush->first;

	while(li) {
		char *dir = (char *)li->data;
		e = list_search(ftp->cache, (listsearchfunc)cache_search, dir);
		if(e) {
			ftp_trace("flushed directory '%s'\n", dir);
			list_delitem(ftp->cache, e);
		} else
			ftp_trace("error flushing directory '%s' (not cached)\n", dir);

		li = li->next;
	}

	list_clear(ftp->dirs_to_flush);
}

void ftp_cache_clear(void)
{
	list_clear(ftp->dirs_to_flush);
	list_clear(ftp->cache);
	ftp_trace("clear whole directory cache\n");
}

/* PATH is NOT quoted */
/* returns a directory from the cache, or 0 if not found
 */
rdirectory *ftp_cache_get_directory(const char *path)
{
	listitem *li;
	char *dir_to_search_for;

	if(path)
		dir_to_search_for = ftp_path_absolute(path);
	else
		dir_to_search_for = xstrdup(ftp->curdir);

	li = list_search(ftp->cache, (listsearchfunc)cache_search,
					 dir_to_search_for);

	if(li && gvCacheTimeout &&
	   ((rdirectory *)li->data)->timestamp + gvCacheTimeout <= time(0))
	{
		/* directory cache has timed out */

		ftp_trace("Directory cache for '%s' has timed out\n",
				  dir_to_search_for);
		ftp_cache_flush_mark(dir_to_search_for);
	}
	free(dir_to_search_for);

	if(!li)
		return 0;

	return (rdirectory *)li->data;
}

/* returns a file from the cache, or 0 if not found
 */
rfile *ftp_cache_get_file(const char *path)
{
	rdirectory *rdir;
	rfile *f;
	char *dir;

	if(!path)
		return 0;

	dir = base_dir_xptr(path);
	rdir = ftp_cache_get_directory(dir);
	free(dir);

	if(rdir) {
		f = rdir_get_file(rdir, base_name_ptr(path));
		return f;
	}
	return 0;
}