[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]

[Libguestfs] [PATCH 2/3] New API: find0 (unlimited version of find)



-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming blog: http://rwmj.wordpress.com
Fedora now supports 80 OCaml packages (the OPEN alternative to F#)
http://cocan.org/getting_started_with_ocaml_on_red_hat_and_fedora
>From 8dce31f2c084914c6f1845e40ccbf26aec5a8278 Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones redhat com>
Date: Mon, 19 Oct 2009 17:44:16 +0100
Subject: [PATCH 2/3] New API: find0 (unlimited version of find)

This adds a new API call guestfs_find0, which is like guestfs_find
but mainly doesn't suffer from the protocol limit of the earlier
command.  The earlier command is not deprecated because it is
still very useful.

guestfs_find0 uses a FileOut parameter and writes the results to
an external file.  The filenames in the output are separated by
ASCII NUL characters (so a bit like "find -print0").

There is also the addition of a regression test for this command.
---
 daemon/find.c             |   99 +++++++++++++++++++++++++++++++++++++++++++++
 regressions/Makefile.am   |    1 +
 regressions/test-find0.sh |   39 ++++++++++++++++++
 src/MAX_PROC_NR           |    2 +-
 src/generator.ml          |   37 ++++++++++++++++-
 5 files changed, 176 insertions(+), 2 deletions(-)
 create mode 100755 regressions/test-find0.sh

diff --git a/daemon/find.c b/daemon/find.c
index 2147c57..1cd3a7a 100644
--- a/daemon/find.c
+++ b/daemon/find.c
@@ -129,3 +129,102 @@ do_find (const char *dir)
 
   return res;			/* caller frees */
 }
+
+/* The code below assumes each path returned can fit into a protocol
+ * chunk.  If this turns out not to be true at some point in the
+ * future then we'll need to modify the code a bit to handle it, or
+ * make the chunk size a bit bigger.
+ */
+#if PATH_MAX > GUESTFS_MAX_CHUNK_SIZE
+#error "PATH_MAX > GUESTFS_MAX_CHUNK_SIZE"
+#endif
+
+/* Has one FileOut parameter. */
+int
+do_find0 (const char *dir)
+{
+  struct stat statbuf;
+  int r;
+  FILE *fp;
+  char *cmd;
+  char *sysrootdir;
+  size_t sysrootdirlen, len;
+  char str[GUESTFS_MAX_CHUNK_SIZE];
+
+  sysrootdir = sysroot_path (dir);
+  if (!sysrootdir) {
+    reply_with_perror ("malloc");
+    return -1;
+  }
+
+  r = stat (sysrootdir, &statbuf);
+  if (r == -1) {
+    reply_with_perror ("%s", dir);
+    free (sysrootdir);
+    return -1;
+  }
+  if (!S_ISDIR (statbuf.st_mode)) {
+    reply_with_error ("%s: not a directory", dir);
+    free (sysrootdir);
+    return -1;
+  }
+
+  sysrootdirlen = strlen (sysrootdir);
+
+  if (asprintf_nowarn (&cmd, "find %Q -print0", sysrootdir) == -1) {
+    reply_with_perror ("asprintf");
+    free (sysrootdir);
+    return -1;
+  }
+
+  if (verbose)
+    fprintf (stderr, "%s\n", cmd);
+
+  fp = popen (cmd, "r");
+  if (fp == NULL) {
+    reply_with_perror ("%s", cmd);
+    free (cmd);
+    return -1;
+  }
+  free (cmd);
+
+  /* Now we must send the reply message, before the file contents.  After
+   * this there is no opportunity in the protocol to send any error
+   * message back.  Instead we can only cancel the transfer.
+   */
+  reply (NULL, NULL);
+
+  while ((r = input_to_nul (fp, str, GUESTFS_MAX_CHUNK_SIZE)) > 0) {
+    if (verbose)
+      printf ("find0 string: %s\n", str);
+
+    len = strlen (str);
+    if (len <= sysrootdirlen)
+      continue;
+
+    /* Remove the directory part of the path before sending it. */
+    if (send_file_write (str + sysrootdirlen, r - sysrootdirlen) < 0) {
+      pclose (fp);
+      return -1;
+    }
+  }
+
+  if (ferror (fp)) {
+    perror (dir);
+    send_file_end (1);		/* Cancel. */
+    pclose (fp);
+    return -1;
+  }
+
+  if (pclose (fp) != 0) {
+    perror (dir);
+    send_file_end (1);		/* Cancel. */
+    return -1;
+  }
+
+  if (send_file_end (0))	/* Normal end of file. */
+    return -1;
+
+  return 0;
+}
+
diff --git a/regressions/Makefile.am b/regressions/Makefile.am
index 9112b94..058b60d 100644
--- a/regressions/Makefile.am
+++ b/regressions/Makefile.am
@@ -26,6 +26,7 @@ TESTS = \
 	rhbz503169c13.sh \
 	test-cancellation-download-librarycancels.sh \
 	test-cancellation-upload-daemoncancels.sh \
+	test-find0.sh \
 	test-noexec-stack.pl \
 	test-qemudie-killsub.sh \
 	test-qemudie-midcommand.sh \
diff --git a/regressions/test-find0.sh b/regressions/test-find0.sh
new file mode 100755
index 0000000..4849b64
--- /dev/null
+++ b/regressions/test-find0.sh
@@ -0,0 +1,39 @@
+#!/bin/sh -
+# libguestfs
+# Copyright (C) 2009 Red Hat Inc.
+#
+# 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.
+#
+# This program 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 this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+# Test find0 call.
+
+set -e
+
+rm -f test.out
+
+../fish/guestfish <<'EOF'
+add-ro ../images/test.iso
+run
+mount-ro /dev/sda /
+find0 / test.out
+EOF
+
+n=$(tr '\0' '\n' < test.out | grep '^known-[1-5]' | wc -l)
+[ "$n" = 5 ] || {
+  echo find0: Invalid list of files
+  tr '\0' '\n' < test.out
+  exit 1
+}
+
+rm -f test.out
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index 6bb2f98..0f11735 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-195
+196
diff --git a/src/generator.ml b/src/generator.ml
index 74890b4..cea5178 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -2525,7 +2525,9 @@ then the returned list from C<guestfs_find> C</tmp> would be
 If C<directory> is not a directory, then this command returns
 an error.
 
-The returned list is sorted.");
+The returned list is sorted.
+
+See also C<guestfs_find0>.");
 
   ("e2fsck_f", (RErr, [Device "device"]), 108, [],
    [], (* lvresize tests this *)
@@ -3610,6 +3612,39 @@ You can use this command to test the connection through to the daemon.
 
 See also C<guestfs_ping_daemon>.");
 
+  ("find0", (RErr, [Pathname "directory"; FileOut "files"]), 196, [],
+   [], (* There is a regression test for this. *)
+   "find all files and directories, returning NUL-separated list",
+   "\
+This command lists out all files and directories, recursively,
+starting at C<directory>, placing the resulting list in the
+external file called C<files>.
+
+This command works the same way as C<guestfs_find> with the
+following exceptions:
+
+=over 4
+
+=item *
+
+The resulting list is written to an external file.
+
+=item *
+
+Items (filenames) in the result are separated
+by C<\\0> characters.  See L<find(1)> option I<-print0>.
+
+=item *
+
+This command is not limited in the number of names that it
+can return.
+
+=item *
+
+The result list is not sorted.
+
+=back");
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions
-- 
1.6.5.rc2


[Date Prev][Date Next]   [Thread Prev][Thread Next]   [Thread Index] [Date Index] [Author Index]