/**
* =========================================================================
* File : file_util.cpp
* Project : 0 A.D.
* Description : utility functions for file and path handling modules
* =========================================================================
*/
// license: GPL; see lib/license.txt
#include "precompiled.h"
#include <queue>
#include "lib/regex.h"
#include "file_internal.h"
static bool dirent_less(const DirEnt& d1, const DirEnt& d2)
{
return strcmp(d1.name, d2.name) < 0;
}
// enumerate all directory entries in <P_path>; add to container and
// then sort it by filename.
LibError file_get_sorted_dirents(const char* P_path, DirEnts& dirents)
{
DirIterator d;
RETURN_ERR(dir_open(P_path, &d));
dirents.reserve(50); // preallocate for efficiency
DirEnt ent;
for(;;)
{
LibError ret = dir_next_ent(&d, &ent);
if(ret == ERR::DIR_END)
break;
RETURN_ERR(ret);
ent.name = file_make_unique_fn_copy(ent.name);
dirents.push_back(ent);
}
std::sort(dirents.begin(), dirents.end(), dirent_less);
(void)dir_close(&d);
return INFO::OK;
}
// call <cb> for each file and subdirectory in <dir> (alphabetical order),
// passing the entry name (not full path!), stat info, and <user>.
//
// first builds a list of entries (sorted) and remembers if an error occurred.
// if <cb> returns non-zero, abort immediately and return that; otherwise,
// return first error encountered while listing files, or 0 on success.
//
// rationale:
// this makes file_enum and zip_enum slightly incompatible, since zip_enum
// returns the full path. that's necessary because VFS zip_cb
// has no other way of determining what VFS dir a Zip file is in,
// since zip_enum enumerates all files in the archive (not only those
// in a given dir). no big deal though, since add_ent has to
// special-case Zip files anyway.
// the advantage here is simplicity, and sparing callbacks the trouble
// of converting from/to native path (we just give 'em the dirent name).
LibError file_enum(const char* P_path, const FileCB cb, const uintptr_t user)
{
LibError stat_err = INFO::OK; // first error encountered by stat()
LibError cb_err = INFO::OK; // first error returned by cb
DirEnts dirents;
RETURN_ERR(file_get_sorted_dirents(P_path, dirents));
// call back for each entry (now sorted);
// first, expand each DirEnt to full struct stat (we store as such to
// reduce memory use and therefore speed up sorting)
struct stat s;
memset(&s, 0, sizeof(s));
// .. not needed for plain files (OS opens them; memento doesn't help)
const uintptr_t memento = 0;
for(DirEntCIt it = dirents.begin(); it != dirents.end(); ++it)
{
const DirEnt& dirent = *it;
s.st_mode = (dirent.size == -1)? S_IFDIR : S_IFREG;
s.st_size = dirent.size;
s.st_mtime = dirent.mtime;
LibError ret = cb(dirent.name, &s, memento, user);
if(ret != INFO::CB_CONTINUE)
{
cb_err = ret; // first error (since we now abort)
break;
}
}
if(cb_err != INFO::OK)
return cb_err;
return stat_err;
}
// retrieve the next (order is unspecified) dir entry matching <filter>.
// return 0 on success, ERR::DIR_END if no matching entry was found,
// or a negative error code on failure.
// filter values:
// - 0: anything;
// - "/": any subdirectory;
// - "/|<pattern>": any subdirectory, or as below with <pattern>;
// - <pattern>: any file whose name matches; ? and * wildcards are allowed.
//
// note that the directory entries are only scanned once; after the
// end is reached (-> ERR::DIR_END returned), no further entries can
// be retrieved, even if filter changes (which shouldn't happen - see impl).
//
// rationale: we do not sort directory entries alphabetically here.
// most callers don't need it and the overhead is considerable
// (we'd have to store all entries in a vector). it is left up to
// higher-level code such as VfsUtil.
LibError dir_filtered_next_ent(DirIterator* di, DirEnt* ent, const char* filter)
{
// warn if scanning the directory twice with different filters
// (this used to work with dir/file because they were stored separately).
// it is imaginable that someone will want to change it, but until
// there's a good reason, leave this check in. note: only comparing
// pointers isn't 100% certain, but it's safe enough and easy.
if(!di->filter_latched)
{
di->filter = filter;
di->filter_latched = 1;
}
if(di->filter != filter)
debug_warn("filter has changed for this directory. are you scanning it twice?");
bool want_dir = true;
if(filter)
{
// directory
if(filter[0] == '/')
{
// .. and also files
if(filter[1] == '|')
filter += 2;
}
// file only
else
want_dir = false;
}
// loop until ent matches what is requested, or end of directory.
for(;;)
{
RETURN_ERR(xdir_next_ent(di, ent));
if(DIRENT_IS_DIR(ent))
{
if(want_dir)
break;
}
else
{
// (note: filter = 0 matches anything)
if(match_wildcard(ent->name, filter))
break;
}
}
return INFO::OK;
}
// call <cb> for each entry matching <user_filter> (see vfs_next_dirent) in
// directory <path>; if flags & VFS_DIR_RECURSIVE, entries in
// subdirectories are also returned.
//
// note: EnumDirEntsCB path and ent are only valid during the callback.
LibError vfs_dir_enum(const char* start_path, uint flags, const char* user_filter,
DirEnumCB cb, void* context)
{
debug_assert((flags & ~(VFS_DIR_RECURSIVE)) == 0);
const bool recursive = (flags & VFS_DIR_RECURSIVE) != 0;
char filter_buf[PATH_MAX];
const char* filter = user_filter;
bool user_filter_wants_dirs = true;
if(user_filter)
{
if(user_filter[0] != '/')
user_filter_wants_dirs = false;
// we need subdirectories and the caller hasn't already requested them
if(recursive && !user_filter_wants_dirs)
{
snprintf(filter_buf, sizeof(filter_buf), "/|%s", user_filter);
filter = filter_buf;
}
}
// note: FIFO queue instead of recursion is much more efficient
// (less stack usage; avoids seeks by reading all entries in a
// directory consecutively)
std::queue<const char*> dir_queue;
dir_queue.push(file_make_unique_fn_copy(start_path));
// for each directory:
do
{
// get current directory path from queue
// note: can't refer to the queue contents - those are invalidated
// as soon as a directory is pushed onto it.
PathPackage pp;
(void)path_package_set_dir(&pp, dir_queue.front());
dir_queue.pop();
Handle hdir = vfs_dir_open(pp.path);
if(hdir <= 0)
{
debug_warn("vfs_open_dir failed");
continue;
}
// for each entry (file, subdir) in directory:
DirEnt ent;
while(vfs_dir_next_ent(hdir, &ent, filter) == 0)
{
// build complete path (DirEnt only stores entry name)
(void)path_package_append_file(&pp, ent.name);
const char* atom_path = file_make_unique_fn_copy(pp.path);
if(DIRENT_IS_DIR(&ent))
{
if(recursive)
dir_queue.push(atom_path);
if(user_filter_wants_dirs)
cb(atom_path, &ent, context);
}
else
cb(atom_path, &ent, context);
}
vfs_dir_close(hdir);
}
while(!dir_queue.empty());
return INFO::OK;
}
// fill V_next_fn (which must be big enough for PATH_MAX chars) with
// the next numbered filename according to the pattern defined by V_fn_fmt.
// <nfi> must be initially zeroed (e.g. by defining as static) and passed
// each time.
// if <use_vfs> (default), the paths are treated as VFS paths; otherwise,
// file.cpp's functions are used. this is necessary because one of
// our callers needs a filename for VFS archive files.
//
// this function is useful when creating new files which are not to
// overwrite the previous ones, e.g. screenshots.
// example for V_fn_fmt: "screenshots/screenshot%04d.png".
void next_numbered_filename(const char* fn_fmt,
NextNumberedFilenameInfo* nfi, char* next_fn, bool use_vfs)
{
// (first call only:) scan directory and set next_num according to
// highest matching filename found. this avoids filling "holes" in
// the number series due to deleted files, which could be confusing.
// example: add 1st and 2nd; [exit] delete 1st; [restart]
// add 3rd -> without this measure it would get number 1, not 3.
if(nfi->next_num == 0)
{
char dir[PATH_MAX];
path_dir_only(fn_fmt, dir);
const char* name_fmt = path_name_only(fn_fmt);
int max_num = -1; int num;
DirEnt ent;
if(use_vfs)
{
Handle hd = vfs_dir_open(dir);
if(hd > 0)
{
while(vfs_dir_next_ent(hd, &ent, 0) == INFO::OK)
{
if(!DIRENT_IS_DIR(&ent) && sscanf(ent.name, name_fmt, &num) == 1)
max_num = std::max(num, max_num);
}
(void)vfs_dir_close(hd);
}
}
else
{
DirIterator it;
if(dir_open(dir, &it) == INFO::OK)
{
while(dir_next_ent(&it, &ent) == INFO::OK)
if(!DIRENT_IS_DIR(&ent) && sscanf(ent.name, name_fmt, &num) == 1)
max_num = std::max(num, max_num);
(void)dir_close(&it);
}
}
nfi->next_num = max_num+1;
}
bool (*exists)(const char* fn) = use_vfs? vfs_exists : file_exists;
// now increment number until that file doesn't yet exist.
// this is fairly slow, but typically only happens once due
// to scan loop above. (we still need to provide for looping since
// someone may have added files in the meantime)
// binary search isn't expected to improve things.
do
snprintf(next_fn, PATH_MAX, fn_fmt, nfi->next_num++);
while(exists(next_fn));
}