Du kannst nicht mehr als 25 Themen auswählen
Themen müssen entweder mit einem Buchstaben oder einer Ziffer beginnen. Sie können Bindestriche („-“) enthalten und bis zu 35 Zeichen lang sein.
136 Zeilen
5.1 KiB
136 Zeilen
5.1 KiB
;;;; Source-file cache
|
|
;;;
|
|
;;; To robustly find source locations in CMUCL and SBCL it's useful to
|
|
;;; have the exact source code that the loaded code was compiled from.
|
|
;;; In this source we can accurately find the right location, and from
|
|
;;; that location we can extract a "snippet" of code to show what the
|
|
;;; definition looks like. Emacs can use this snippet in a best-match
|
|
;;; search to locate the right definition, which works well even if
|
|
;;; the buffer has been modified.
|
|
;;;
|
|
;;; The idea is that if a definition previously started with
|
|
;;; `(define-foo bar' then it probably still does.
|
|
;;;
|
|
;;; Whenever we see that the file on disk has the same
|
|
;;; `file-write-date' as a location we're looking for we cache the
|
|
;;; whole file inside Lisp. That way we will still have the matching
|
|
;;; version even if the file is later modified on disk. If the file is
|
|
;;; later recompiled and reloaded then we replace our cache entry.
|
|
;;;
|
|
;;; This code has been placed in the Public Domain. All warranties
|
|
;;; are disclaimed.
|
|
|
|
(defpackage swank/source-file-cache
|
|
(:use cl)
|
|
(:import-from swank/backend
|
|
defimplementation buffer-first-change
|
|
guess-external-format
|
|
find-external-format)
|
|
(:export
|
|
get-source-code
|
|
source-cache-get ;FIXME: isn't it odd that both are exported?
|
|
|
|
*source-snippet-size*
|
|
read-snippet
|
|
read-snippet-from-string
|
|
))
|
|
|
|
(in-package swank/source-file-cache)
|
|
|
|
(defvar *cache-sourcecode* t
|
|
"When true complete source files are cached.
|
|
The cache is used to keep known good copies of the source text which
|
|
correspond to the loaded code. Finding definitions is much more
|
|
reliable when the exact source is available, so we cache it in case it
|
|
gets edited on disk later.")
|
|
|
|
(defvar *source-file-cache* (make-hash-table :test 'equal)
|
|
"Cache of source file contents.
|
|
Maps from truename to source-cache-entry structure.")
|
|
|
|
(defstruct (source-cache-entry
|
|
(:conc-name source-cache-entry.)
|
|
(:constructor make-source-cache-entry (text date)))
|
|
text date)
|
|
|
|
(defimplementation buffer-first-change (filename)
|
|
"Load a file into the cache when the user modifies its buffer.
|
|
This is a win if the user then saves the file and tries to M-. into it."
|
|
(unless (source-cached-p filename)
|
|
(ignore-errors
|
|
(source-cache-get filename (file-write-date filename))))
|
|
nil)
|
|
|
|
(defun get-source-code (filename code-date)
|
|
"Return the source code for FILENAME as written on DATE in a string.
|
|
If the exact version cannot be found then return the current one from disk."
|
|
(or (source-cache-get filename code-date)
|
|
(read-file filename)))
|
|
|
|
(defun source-cache-get (filename date)
|
|
"Return the source code for FILENAME as written on DATE in a string.
|
|
Return NIL if the right version cannot be found."
|
|
(when *cache-sourcecode*
|
|
(let ((entry (gethash filename *source-file-cache*)))
|
|
(cond ((and entry (equal date (source-cache-entry.date entry)))
|
|
;; Cache hit.
|
|
(source-cache-entry.text entry))
|
|
((or (null entry)
|
|
(not (equal date (source-cache-entry.date entry))))
|
|
;; Cache miss.
|
|
(if (equal (file-write-date filename) date)
|
|
;; File on disk has the correct version.
|
|
(let ((source (read-file filename)))
|
|
(setf (gethash filename *source-file-cache*)
|
|
(make-source-cache-entry source date))
|
|
source)
|
|
nil))))))
|
|
|
|
(defun source-cached-p (filename)
|
|
"Is any version of FILENAME in the source cache?"
|
|
(if (gethash filename *source-file-cache*) t))
|
|
|
|
(defun read-file (filename)
|
|
"Return the entire contents of FILENAME as a string."
|
|
(with-open-file (s filename :direction :input
|
|
:external-format (or (guess-external-format filename)
|
|
(find-external-format "latin-1")
|
|
:default))
|
|
(let* ((string (make-string (file-length s)))
|
|
(length (read-sequence string s)))
|
|
(subseq string 0 length))))
|
|
|
|
;;;; Snippets
|
|
|
|
(defvar *source-snippet-size* 256
|
|
"Maximum number of characters in a snippet of source code.
|
|
Snippets at the beginning of definitions are used to tell Emacs what
|
|
the definitions looks like, so that it can accurately find them by
|
|
text search.")
|
|
|
|
(defun read-snippet (stream &optional position)
|
|
"Read a string of upto *SOURCE-SNIPPET-SIZE* characters from STREAM.
|
|
If POSITION is given, set the STREAM's file position first."
|
|
(when position
|
|
(file-position stream position))
|
|
#+sbcl (skip-comments-and-whitespace stream)
|
|
(read-upto-n-chars stream *source-snippet-size*))
|
|
|
|
(defun read-snippet-from-string (string &optional position)
|
|
(with-input-from-string (s string)
|
|
(read-snippet s position)))
|
|
|
|
(defun skip-comments-and-whitespace (stream)
|
|
(case (peek-char nil stream nil nil)
|
|
((#\Space #\Tab #\Newline #\Linefeed #\Page)
|
|
(read-char stream)
|
|
(skip-comments-and-whitespace stream))
|
|
(#\;
|
|
(read-line stream)
|
|
(skip-comments-and-whitespace stream))))
|
|
|
|
(defun read-upto-n-chars (stream n)
|
|
"Return a string of upto N chars from STREAM."
|
|
(let* ((string (make-string n))
|
|
(chars (read-sequence string stream)))
|
|
(subseq string 0 chars)))
|