Add option to download non-HTML links directly after their parent pag…

…e when downloading recursively

because it's more likely to download temporary links before they expire because it's more similar to the browsing experience

doc/wget.texi

@@ -1916,6 +1916,10 @@ case.
 Turn on recursive retrieving.  @xref{Recursive Download}, for more
 details.  The default maximum depth is 5.
 
+@item --queue-type=@var{queuetype}
+Specify the queue type (@pxref{Recursive Download}). Accepted values are @samp{fifo}
+(the default) and @samp{browser}.
+
 @item -l @var{depth}
 @itemx --level=@var{depth}
 Specify recursion maximum depth level @var{depth} (@pxref{Recursive
@@ -2296,6 +2300,12 @@ documents linked by them, and so on.  In other words, Wget first
 downloads the documents at depth 1, then those at depth 2, and so on
 until the specified maximum depth.
 
+The @dfn{queue type} is FIFO (default) or browser. FIFO download the
+first enqueued files first. Browser download non-HTML links directly
+after their parent page. If the parent page contain temporary links
+this can prevent that links expire before they're downloaded. Pages
+sometimes use temporary links to prevent direct links to files.
+
 The maximum @dfn{depth} to which the retrieval may descend is specified
 with the @samp{-l} option.  The default maximum depth is five layers.
 

src/init.c

@@ -104,6 +104,7 @@ CMD_DECLARE (cmd_spec_htmlify);
 CMD_DECLARE (cmd_spec_mirror);
 CMD_DECLARE (cmd_spec_prefer_family);
 CMD_DECLARE (cmd_spec_progress);
+CMD_DECLARE (cmd_spec_queue_type);
 CMD_DECLARE (cmd_spec_recursive);
 CMD_DECLARE (cmd_spec_regex_type);
 CMD_DECLARE (cmd_spec_restrict_file_names);
@@ -247,6 +248,7 @@ static const struct {
   { "proxypasswd",      &opt.proxy_passwd,      cmd_string }, /* deprecated */
   { "proxypassword",    &opt.proxy_passwd,      cmd_string },
   { "proxyuser",        &opt.proxy_user,        cmd_string },
+  { "queuetype",        &opt.queue_type,        cmd_spec_queue_type },
   { "quiet",            &opt.quiet,             cmd_boolean },
   { "quota",            &opt.quota,             cmd_bytes_sum },
 #ifdef HAVE_SSL
@@ -403,6 +405,8 @@ defaults (void)
   opt.restrict_files_nonascii = false;
   opt.restrict_files_case = restrict_no_case_restriction;
 
+  opt.queue_type = queue_type_fifo;
+
   opt.regex_type = regex_type_posix;
 
   opt.max_redirect = 20;
@@ -1441,6 +1445,23 @@ cmd_spec_recursive (const char *com, const char *val, void *place_ignored _GL_UN
   return true;
 }
 
+/* Validate --queue-type and set the choice.  */
+
+static bool
+cmd_spec_queue_type (const char *com, const char *val, void *place_ignored _GL_UNUSED)
+{
+  static const struct decode_item choices[] = {
+    { "fifo", queue_type_fifo },
+    { "browser", queue_type_browser },
+  };
+  int queue_type = queue_type_fifo;
+  int ok = decode_string (val, choices, countof (choices), &queue_type);
+  if (!ok)
+    fprintf (stderr, _("%s: %s: Invalid value %s.\n"), exec_name, com, quote (val));
+  opt.queue_type = queue_type;
+  return ok;
+}
+
 /* Validate --regex-type and set the choice.  */
 
 static bool

src/main.c

@@ -272,6 +272,7 @@ static struct cmdline_option option_data[] =
     { "proxy-passwd", 0, OPT_VALUE, "proxypassword", -1 }, /* deprecated */
     { "proxy-password", 0, OPT_VALUE, "proxypassword", -1 },
     { "proxy-user", 0, OPT_VALUE, "proxyuser", -1 },
+    { "queue-type", 0, OPT_VALUE, "queuetype", -1 },
     { "quiet", 'q', OPT_BOOLEAN, "quiet", -1 },
     { "quota", 'Q', OPT_VALUE, "quota", -1 },
     { "random-file", 0, OPT_VALUE, "randomfile", -1 },
@@ -736,6 +737,8 @@ WARC options:\n"),
 Recursive download:\n"),
     N_("\
   -r,  --recursive                 specify recursive download\n"),
+    N_("\
+       --queue-type=TYPE           queue type (fifo|browser).\n"),
     N_("\
   -l,  --level=NUMBER              maximum recursion depth (inf or 0 for infinite)\n"),
     N_("\

src/options.h

@@ -46,6 +46,10 @@ struct options
   bool relative_only;           /* Follow only relative links. */
   bool no_parent;               /* Restrict access to the parent
                                    directory.  */
+  enum {
+    queue_type_fifo,
+    queue_type_browser
+  } queue_type;                 /* Recursion queue type */
   int reclevel;                 /* Maximum level of recursion */
   bool dirstruct;               /* Do we build the directory structure
                                    as we go along? */

src/recur.c

@@ -90,13 +90,16 @@ url_queue_delete (struct url_queue *queue)
 
 /* Enqueue a URL in the queue.  The queue is FIFO: the items will be
    retrieved ("dequeued") from the queue in the order they were placed
-   into it.  */
+   into it. Or browser: Non-HTML links are retrieved directly after
+   their parent page. */
 
 static void
 url_enqueue (struct url_queue *queue, struct iri *i,
              const char *url, const char *referer, int depth,
              bool html_allowed, bool css_allowed)
 {
+  int append = opt.queue_type == queue_type_fifo || html_allowed;
+
   struct queue_element *qel = xnew (struct queue_element);
   qel->iri = i;
   qel->url = url;
@@ -110,20 +113,31 @@ url_enqueue (struct url_queue *queue, struct iri *i,
   if (queue->count > queue->maxcount)
     queue->maxcount = queue->count;
 
-  DEBUGP (("Enqueuing %s at depth %d\n",
+  DEBUGP (("%s %s at depth %d\n", append ? "Appending" : "Prepending",
            quotearg_n_style (0, escape_quoting_style, url), depth));
   DEBUGP (("Queue count %d, maxcount %d.\n", queue->count, queue->maxcount));
 
   if (i)
-    DEBUGP (("[IRI Enqueuing %s with %s\n", quote_n (0, url),
-             i->uri_encoding ? quote_n (1, i->uri_encoding) : "None"));
+    DEBUGP (("[IRI %s %s with %s\n", append ? "Appending" : "Prepending",
+            quote_n (0, url), i->uri_encoding ? quote_n (1, i->uri_encoding) : "None"));
 
-  if (queue->tail)
-    queue->tail->next = qel;
-  queue->tail = qel;
+  if (append)
+  {
+    if (queue->tail)
+      queue->tail->next = qel;
+    queue->tail = qel;
+  }
+  else
+  {
+    if (queue->head)
+      qel->next = queue->head;
+    queue->head = qel;
+  }
 
   if (!queue->head)
     queue->head = queue->tail;
+  if (!queue->tail)
+    queue->tail = queue->head;
 }
 
 /* Take a URL out of the queue.  Return true if this operation