--- /dev/null
+(* Copyright (C) 2004-2005, HELM Team.
+ *
+ * This file is part of HELM, an Hypertextual, Electronic
+ * Library of Mathematics, developed at the Computer Science
+ * Department, University of Bologna, Italy.
+ *
+ * HELM 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.
+ *
+ * HELM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with HELM; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
+ * MA 02111-1307, USA.
+ *
+ * For details, see the HELM World-Wide-Web page,
+ * http://helm.cs.unibo.it/
+ *)
+
+(* $Id$ *)
+
+open Printf
+
+open Http_getter_misc
+open Http_getter_types
+
+exception Not_found'
+exception Resource_not_found of string * string (** method, uri *)
+
+let index_fname = "INDEX"
+
+(******************************* HELPERS **************************************)
+
+let trailing_slash_RE = Pcre.regexp "/$"
+let relative_RE_raw = "(^[^/]+(/[^/]+)*/?$)"
+let relative_RE = Pcre.regexp relative_RE_raw
+let file_scheme_RE_raw = "(^file://)"
+let extended_file_scheme_RE = Pcre.regexp "(^file:/+)"
+let file_scheme_RE = Pcre.regexp (relative_RE_raw ^ "|" ^ file_scheme_RE_raw)
+let http_scheme_RE = Pcre.regexp "^http://"
+let newline_RE = Pcre.regexp "\\n"
+let cic_scheme_sep_RE = Pcre.regexp ":/"
+let gz_suffix = ".gz"
+let gz_suffix_len = String.length gz_suffix
+
+ (* file:///bla -> bla, bla -> bla *)
+let path_of_file_url url =
+ assert (Pcre.pmatch ~rex:file_scheme_RE url);
+ if Pcre.pmatch ~rex:relative_RE url then
+ url
+ else (* absolute path, add heading "/" if missing *)
+ "/" ^ (Pcre.replace ~rex:extended_file_scheme_RE url)
+
+let strip_gz_suffix fname =
+ if extension fname = gz_suffix then
+ String.sub fname 0 (String.length fname - gz_suffix_len)
+ else
+ fname
+
+let normalize_root uri = (* add trailing slash to roots *)
+ try
+ if uri.[String.length uri - 1] = ':' then uri ^ "/"
+ else uri
+ with Invalid_argument _ -> uri
+
+let remove_duplicates l =
+ Http_getter_misc.list_uniq (List.stable_sort Pervasives.compare l)
+
+let has_rdonly l = List.exists ((=) `Read_only) l
+let has_legacy l = List.exists ((=) `Legacy) l
+let is_readwrite attrs = (not (has_legacy attrs) && not (has_rdonly attrs))
+
+let is_file_schema url = Pcre.pmatch ~rex:file_scheme_RE url
+let is_http_schema url = Pcre.pmatch ~rex:http_scheme_RE url
+
+let is_empty_listing files =
+ List.for_all
+ (fun s ->
+ let len = String.length s in
+ len < 4 || String.sub s (len - 4) 4 <> ".xml") files
+
+(************************* GLOBALS PREFIXES **********************************)
+
+ (** associative list regular expressions -> url prefixes
+ * sorted with longest prefixes first *)
+let prefix_map_ref = ref (lazy (
+ List.map
+ (fun (uri_prefix, (url_prefix, attrs)) ->
+ let uri_prefix = normalize_dir uri_prefix in
+ let url_prefix = normalize_dir url_prefix in
+ let regexp = Pcre.regexp ("^(" ^ Pcre.quote uri_prefix ^ ")") in
+ regexp, strip_trailing_slash uri_prefix, url_prefix, attrs)
+ (List.rev (Lazy.force Http_getter_env.prefixes))))
+
+let prefix_map () = !prefix_map_ref
+
+let keep_first l =
+ let cmp (_,x) (_,y) = x = y in
+ let rec aux prev = function
+ | [] -> []
+ | hd::tl -> if cmp prev hd then hd :: aux prev tl else []
+ in
+ match l with
+ | hd :: tl -> hd :: aux hd tl
+ | _ -> assert false
+;;
+
+ (** given an uri returns the prefixes for it *)
+let lookup uri =
+ let matches =
+ HExtlib.filter_map
+ (fun (rex, _, l, _ as entry) ->
+ try
+ let got = Pcre.extract ~full_match:true ~rex uri in
+ Some (entry, String.length got.(0))
+ with Not_found -> None)
+ (Lazy.force (prefix_map ()))
+ in
+ if matches = [] then raise (Unresolvable_URI uri);
+ List.map fst (keep_first (List.sort (fun (_,l1) (_,l2) -> l2 - l1) matches))
+;;
+
+let get_attrs uri = List.map (fun (_, _, _, attrs) -> attrs) (lookup uri)
+
+(*************************** ACTIONS ******************************************)
+
+let exists_http ~local _ url =
+ if local then false else
+ Http_getter_wget.exists (url ^ gz_suffix) || Http_getter_wget.exists url
+
+let exists_file _ fname =
+ Sys.file_exists (fname ^ gz_suffix) || Sys.file_exists fname
+
+let resolve_http ~must_exists ~local _ url =
+ if local then raise Not_found' else
+ try
+ if must_exists then
+ List.find Http_getter_wget.exists [ url ^ gz_suffix; url ]
+ else
+ url
+ with Not_found -> raise Not_found'
+
+let resolve_file ~must_exists _ fname =
+ try
+ if must_exists then
+ List.find Sys.file_exists [ fname ^ gz_suffix; fname ]
+ else
+ fname
+ with Not_found -> raise Not_found'
+
+let ls_file_single _ path_prefix =
+ let is_dir fname = (Unix.stat fname).Unix.st_kind = Unix.S_DIR in
+ let is_useless dir = try dir.[0] = '.' with _ -> false in
+ let entries = ref [] in
+ try
+ let dir_handle = Unix.opendir path_prefix in
+ (try
+ while true do
+ let entry = Unix.readdir dir_handle in
+ if is_useless entry then
+ ()
+ else if is_dir (path_prefix ^ "/" ^ entry) then
+ entries := normalize_dir entry :: !entries
+ else
+ entries := strip_gz_suffix entry :: !entries
+ done
+ with End_of_file -> Unix.closedir dir_handle);
+ remove_duplicates !entries
+ with Unix.Unix_error (_, "opendir", _) -> []
+
+let ls_http_single ~local _ url_prefix =
+ if local then raise (Resource_not_found ("get","")) else
+ let url = normalize_dir url_prefix ^ index_fname in
+ try
+ let index = Http_getter_wget.get url in
+ Pcre.split ~rex:newline_RE index
+ with Http_client_error _ -> raise (Resource_not_found ("get",url))
+;;
+
+let get_file _ path =
+ if Sys.file_exists (path ^ gz_suffix) then
+ path ^ gz_suffix
+ else if Sys.file_exists path then
+ path
+ else
+ raise Not_found'
+
+let get_http ~local uri url =
+ if local then raise Not_found' else
+ let scheme, path =
+ match Pcre.split ~rex:cic_scheme_sep_RE uri with
+ | [scheme; path] -> scheme, path
+ | _ -> assert false
+ in
+ let cache_name =
+ sprintf "%s%s/%s" (Lazy.force Http_getter_env.cache_dir) scheme path
+ in
+ if Sys.file_exists (cache_name ^ gz_suffix) then
+ cache_name ^ gz_suffix
+ else if Sys.file_exists cache_name then
+ cache_name
+ else begin (* fill cache *)
+ Http_getter_misc.mkdir ~parents:true (Filename.dirname cache_name);
+ (try
+ Http_getter_wget.get_and_save (url ^ gz_suffix) (cache_name ^ gz_suffix);
+ cache_name ^ gz_suffix
+ with Http_client_error _ ->
+ (try
+ Http_getter_wget.get_and_save url cache_name;
+ cache_name
+ with Http_client_error _ ->
+ raise Not_found'))
+ end
+
+let remove_file _ path =
+ if Sys.file_exists (path ^ gz_suffix) then Sys.remove (path ^ gz_suffix);
+ if Sys.file_exists path then Sys.remove path
+
+let remove_http _ _ =
+ prerr_endline "Http_getter_storage.remove: not implemented for HTTP scheme";
+ assert false
+
+(**************************** RESOLUTION OF PREFIXES ************************)
+
+let resolve_prefixes n local write exists uri =
+ let exists_test new_uri =
+ if is_file_schema new_uri then
+ exists_file () (path_of_file_url new_uri)
+ else if is_http_schema new_uri then
+ exists_http ~local () new_uri
+ else false
+ in
+ let rec aux n = function
+ | (rex, _, url_prefix, attrs) :: tl when n > 0->
+ (match write, is_readwrite attrs, exists with
+ | true ,false, _ -> aux n tl
+ | true ,true ,true
+ | false,_ ,true ->
+ let new_uri = (Pcre.replace_first ~rex ~templ:url_prefix uri) in
+ if exists_test new_uri then new_uri::aux (n-1) tl else aux n tl
+ | true ,true ,false
+ | false,_ ,false ->
+ (Pcre.replace_first ~rex ~templ:url_prefix uri) :: (aux (n-1) tl))
+ | _ -> []
+ in
+ aux n (lookup uri)
+
+let resolve_prefix l w e u =
+ match resolve_prefixes 1 l w e u with
+ | hd :: _ -> hd
+ | [] ->
+ raise
+ (Resource_not_found
+ (Printf.sprintf "resolve_prefix write:%b exists:%b" w e,u))
+
+(* uncomment to debug prefix resolution *)
+(*
+let resolve_prefix w e u =
+ prerr_endline
+ ("XXX w=" ^ string_of_bool w ^ " e=" ^ string_of_bool e ^" :" ^ u);
+ let rc = resolve_prefix w e u in
+ prerr_endline ("YYY :" ^ rc ^ "\n");
+ rc
+*)
+
+(************************* DISPATCHERS ***************************************)
+
+type 'a storage_method = {
+ name: string;
+ write: bool;
+ exists: bool;
+ local: bool;
+ file: string -> string -> 'a; (* unresolved uri, resolved uri *)
+ http: string -> string -> 'a; (* unresolved uri, resolved uri *)
+}
+
+let invoke_method storage_method uri url =
+ try
+ if is_file_schema url then
+ storage_method.file uri (path_of_file_url url)
+ else if is_http_schema url then
+ storage_method.http uri url
+ else
+ raise (Unsupported_scheme url)
+ with Not_found' -> raise (Resource_not_found (storage_method.name, uri))
+
+let dispatch_single storage_method uri =
+ assert (extension uri <> gz_suffix);
+ let uri = normalize_root uri in
+ let url =
+ resolve_prefix
+ storage_method.local storage_method.write storage_method.exists uri
+ in
+ invoke_method storage_method uri url
+
+let dispatch_multi storage_method uri =
+ let urls =
+ resolve_prefixes max_int
+ storage_method.local storage_method.write storage_method.exists uri
+ in
+ let rec aux = function
+ | [] -> raise (Resource_not_found (storage_method.name, uri))
+ | url :: tl ->
+ (try
+ invoke_method storage_method uri url
+ with Resource_not_found _ -> aux tl)
+ in
+ aux urls
+
+let dispatch_all storage_method uri =
+ let urls =
+ resolve_prefixes max_int
+ storage_method.local storage_method.write storage_method.exists uri
+ in
+ List.map (fun url -> invoke_method storage_method uri url) urls
+
+(******************************** EXPORTED FUNCTIONS *************************)
+
+let exists ~local s =
+ try
+ dispatch_single
+ { write = false;
+ name = "exists";
+ exists = true;
+ local=local;
+ file = exists_file; http = exists_http ~local; } s
+ with Resource_not_found _ -> false
+
+let resolve ~local ?(must_exists=true) ~writable =
+ (if must_exists then
+ dispatch_multi
+ else
+ dispatch_single)
+ { write = writable;
+ name="resolve";
+ exists = must_exists;
+ local=local;
+ file = resolve_file ~must_exists;
+ http = resolve_http ~local ~must_exists; }
+
+let remove =
+ dispatch_single
+ { write = false;
+ name = "remove";
+ exists=true;
+ local=false;
+ file = remove_file; http = remove_http; }
+
+let filename ~local ?(find = false) =
+ (if find then dispatch_multi else dispatch_single)
+ { write = false;
+ name = "filename";
+ exists=true;
+ local=local;
+ file = get_file; http = get_http ~local ; }
+
+let ls ~local uri_prefix =
+ let ls_all s =
+ try
+ dispatch_all
+ { write=false;
+ name = "ls";
+ exists=true;
+ local=local;
+ file = ls_file_single; http = ls_http_single ~local; } s
+ with Resource_not_found _ -> []
+ in
+ let direct_results = List.flatten (ls_all uri_prefix) in
+ List.fold_left
+ (fun results (_, uri_prefix', _, _) ->
+ if Filename.dirname uri_prefix' = strip_trailing_slash uri_prefix then
+ (Filename.basename uri_prefix' ^ "/") :: results
+ else
+ results)
+ direct_results
+ (Lazy.force (prefix_map ()))
+
+let clean_cache () =
+ ignore (Sys.command
+ (sprintf "rm -rf %s/" (Lazy.force Http_getter_env.cache_dir)))
+
+let list_writable_prefixes _ =
+ HExtlib.filter_map
+ (fun (_,_,url,attrs) ->
+ if is_readwrite attrs then
+ Some url
+ else
+ None)
+ (Lazy.force (prefix_map ()))
+
+let is_legacy uri = List.for_all has_legacy (get_attrs uri)
+
+(* implement this in a fast way! *)
+let is_empty ~local buri =
+ let buri = strip_trailing_slash buri ^ "/" in
+ let files = ls ~local buri in
+ is_empty_listing files
+
+let is_read_only uri =
+ let is_empty_dir path =
+ let files =
+ try
+ if is_file_schema path then
+ ls_file_single () (path_of_file_url path)
+ else if is_http_schema path then
+ ls_http_single ~local:false () path
+ else
+ assert false
+ with Resource_not_found _ -> []
+ in
+ is_empty_listing files
+ in
+ let rec aux found_writable = function
+ | (rex, _, url_prefix, attrs)::tl ->
+ let new_url = (Pcre.replace_first ~rex ~templ:url_prefix uri) in
+ let rdonly = has_legacy attrs || has_rdonly attrs in
+ (match rdonly, is_empty_dir new_url, found_writable with
+ | true, false, _ -> true
+ | true, true, _ -> aux found_writable tl
+ | false, _, _ -> aux true tl)
+ | [] -> not found_writable (* if found_writable then false else true *)
+ in
+ aux false (lookup uri)
+
+let activate_system_mode () =
+ let map = Lazy.force (prefix_map ()) in
+ let map =
+ HExtlib.filter_map
+ (fun ((rex, urip, urlp, attrs) as entry) ->
+ if has_legacy attrs then
+ Some entry
+ else if has_rdonly attrs then
+ Some (rex, urip, urlp, List.filter ((<>) `Read_only) attrs)
+ else
+ None)
+ map
+ in
+ let map = map in (* just to remember that ocamlc 'lazy' is a ... *)
+ prefix_map_ref := (lazy map)
+
+(* eof *)
projects / helm.git / blobdiff