ZDIR

NAME

zdir - Class for work with file-system directories

SYNOPSIS

// This is a stable class, and may not change except for emergencies. It
// is provided in stable builds.
// Create a new directory item that loads in the full tree of the specified
// path, optionally located under some parent path. If parent is "-", then
// loads only the top-level directory, and does not use parent as a path.
CZMQ_EXPORT zdir_t *
zdir_new (const char *path, const char *parent);

// Destroy a directory tree and all children it contains.
CZMQ_EXPORT void
zdir_destroy (zdir_t **self_p);

// Return directory path
CZMQ_EXPORT const char *
zdir_path (zdir_t *self);

// Return last modification time for directory.
CZMQ_EXPORT time_t
zdir_modified (zdir_t *self);

// Return total hierarchy size, in bytes of data contained in all files
// in the directory tree.
CZMQ_EXPORT off_t
zdir_cursize (zdir_t *self);

// Return directory count
CZMQ_EXPORT size_t
zdir_count (zdir_t *self);

// Returns a sorted list of zfile objects; Each entry in the list is a pointer
// to a zfile_t item already allocated in the zdir tree. Do not destroy the
// original zdir tree until you are done with this list.
// Caller owns return value and must destroy it when done.
CZMQ_EXPORT zlist_t *
zdir_list (zdir_t *self);

// Remove directory, optionally including all files that it contains, at
// all levels. If force is false, will only remove the directory if empty.
// If force is true, will remove all files and all subdirectories.
CZMQ_EXPORT void
zdir_remove (zdir_t *self, bool force);

// Calculate differences between two versions of a directory tree.
// Returns a list of zdir_patch_t patches. Either older or newer may
// be null, indicating the directory is empty/absent. If alias is set,
// generates virtual filename (minus path, plus alias).
// Caller owns return value and must destroy it when done.
CZMQ_EXPORT zlist_t *
zdir_diff (zdir_t *older, zdir_t *newer, const char *alias);

// Return full contents of directory as a zdir_patch list.
// Caller owns return value and must destroy it when done.
CZMQ_EXPORT zlist_t *
zdir_resync (zdir_t *self, const char *alias);

// Load directory cache; returns a hash table containing the SHA-1 digests
// of every file in the tree. The cache is saved between runs in .cache.
// Caller owns return value and must destroy it when done.
CZMQ_EXPORT zhash_t *
zdir_cache (zdir_t *self);

// Print contents of directory to open stream
CZMQ_EXPORT void
zdir_fprint (zdir_t *self, FILE *file, int indent);

// Print contents of directory to stdout
CZMQ_EXPORT void
zdir_print (zdir_t *self, int indent);

// Create a new zdir_watch actor instance:
//
// zactor_t *watch = zactor_new (zdir_watch, NULL);
//
// Destroy zdir_watch instance:
//
// zactor_destroy (&watch);
//
// Enable verbose logging of commands and activity:
//
// zstr_send (watch, "VERBOSE");
//
// Subscribe to changes to a directory path:
//
// zsock_send (watch, "ss", "SUBSCRIBE", "directory_path");
//
// Unsubscribe from changes to a directory path:
//
// zsock_send (watch, "ss", "UNSUBSCRIBE", "directory_path");
//
// Receive directory changes:
// zsock_recv (watch, "sp", &path, &patches);
//
// // Delete the received data.
// free (path);
// zlist_destroy (&patches);
CZMQ_EXPORT void
zdir_watch (zsock_t *pipe, void *unused);

// Self test of this class.
CZMQ_EXPORT void
zdir_test (bool verbose);

Please add '@interface' section in './../src/zdir.c'.

DESCRIPTION

The zdir class gives access to the file system index. It will load a directory tree (a directory plus all child directories) into a zdir structure and then let you navigate that structure. It exists mainly to wrap non-portable OS functions to do this.

Please add @discuss section in ./../src/zdir.c.

EXAMPLE

From zdir_test method.

const char *SELFTEST_DIR_RW = "src/selftest-rw";

const char *testbasedir = "zdir-test-dir";
const char *testfile1 = "initial_file";
const char *testfile2 = "test_abc";
char *basedirpath = NULL; // subdir in a test, under SELFTEST_DIR_RW
char *filepath1 = NULL; // pathname to testfile in a test, in dirpath
char *filepath2 = NULL; // pathname to testfile in a test, in dirpath

basedirpath = zsys_sprintf ("%s/%s", SELFTEST_DIR_RW, testbasedir);
assert (basedirpath);
filepath1 = zsys_sprintf ("%s/%s", basedirpath, testfile1);
assert (filepath1);
filepath2 = zsys_sprintf ("%s/%s", basedirpath, testfile2);
assert (filepath2);

/*
char *relfilepath2 = NULL; // pathname to testfile in a test, in dirpath
relfilepath2 = zsys_sprintf ("%s/%s", testbasedir, testfile2);
assert (relfilepath2);
*/

// Make sure old aborted tests do not hinder us
zdir_t *dir = zdir_new (basedirpath, NULL);
if (dir) {
zdir_remove (dir, true);
zdir_destroy (&dir);
}
zsys_file_delete (filepath1);
zsys_file_delete (filepath2);
zsys_dir_delete (basedirpath);

dir = zdir_new ("does-not-exist", NULL);
if (dir) {
zdir_remove (dir, true);
zdir_destroy (&dir);
}

// need to create a file in the test directory we're watching
// in order to ensure the directory exists
zfile_t *initfile = zfile_new (basedirpath, testfile1);
assert (initfile);
zfile_output (initfile);
fprintf (zfile_handle (initfile), "initial file\n");
zfile_close (initfile);
zfile_destroy (&initfile);

zdir_t *older = zdir_new (basedirpath, NULL);
assert (older);
if (verbose) {
printf ("\n");
zdir_dump (older, 0);
}
zdir_t *newer = zdir_new (SELFTEST_DIR_RW, NULL);
assert (newer);
zlist_t *patches = zdir_diff (older, newer, "/");
assert (patches);
while (zlist_size (patches)) {
zdir_patch_t *patch = (zdir_patch_t *) zlist_pop (patches);
zdir_patch_destroy (&patch);
}
zlist_destroy (&patches);
zdir_destroy (&older);
zdir_destroy (&newer);

zdir_t *nosuch = zdir_new ("does-not-exist", NULL);
assert (nosuch == NULL);

// zdir_watch test:
zactor_t *watch = zactor_new (zdir_watch, NULL);
assert (watch);

int synced;
if (verbose) {
zsock_send (watch, "s", "VERBOSE");
synced = zsock_wait(watch);
assert ( synced == 0);
}

// wait for initial file to become 'stable'
#ifdef CZMQ_BUILD_DRAFT_API
zclock_sleep ((int)zsys_file_stable_age_msec() + 50);
#else
zclock_sleep (5050);
#endif

zsock_send (watch, "si", "TIMEOUT", 100);
synced = zsock_wait(watch);
assert (synced == 0);

zsock_send (watch, "ss", "SUBSCRIBE", basedirpath);
synced = zsock_wait(watch);
assert(synced == 0);

zsock_send (watch, "ss", "UNSUBSCRIBE", basedirpath);
synced = zsock_wait(watch);
assert(synced == 0);

zsock_send (watch, "ss", "SUBSCRIBE", basedirpath);
synced = zsock_wait(watch);
assert(synced == 0);

zfile_t *newfile = zfile_new (basedirpath, testfile2);
zfile_output (newfile);
fprintf (zfile_handle (newfile), "test file\n");
zfile_close (newfile);

zpoller_t *watch_poll = zpoller_new (watch, NULL);

// poll for a certain timeout before giving up and failing the test
void* polled = NULL;
#ifdef CZMQ_BUILD_DRAFT_API
polled = zpoller_wait(watch_poll, (int)zsys_file_stable_age_msec() + 150);
#else
polled = zpoller_wait(watch_poll, 5150);
#endif
assert (polled == watch);

// wait for notification of the file being added
char *path;
int rc = zsock_recv (watch, "sp", &path, &patches);
assert (rc == 0);

assert (streq (path, basedirpath));
freen (path);

if (verbose)
zsys_debug("zdir_test() : added : zlist_size (patches)=%d",
zlist_size (patches) );
assert (zlist_size (patches) == 1);

zdir_patch_t *patch = (zdir_patch_t *) zlist_pop (patches);
if (verbose)
zsys_debug("zdir_test() : added : zdir_patch_path (patch)='%s'",
zdir_patch_path (patch) );
assert (streq (zdir_patch_path (patch), basedirpath));

zfile_t *patch_file = zdir_patch_file (patch);
if (verbose)
zsys_debug("zdir_test() : added : zfile_filename (patch_file, \"\")='%s'",
zfile_filename (patch_file, "") );
assert (streq (zfile_filename (patch_file, ""), filepath2));

zdir_patch_destroy (&patch);
zlist_destroy (&patches);

// remove the file
zfile_remove (newfile);
zfile_destroy (&newfile);

// poll for a certain timeout before giving up and failing the test.
#ifdef CZMQ_BUILD_DRAFT_API
polled = zpoller_wait(watch_poll, (int)zsys_file_stable_age_msec() + 150);
#else
polled = zpoller_wait(watch_poll, 5150);
#endif
assert (polled == watch);

// wait for notification of the file being removed
rc = zsock_recv (watch, "sp", &path, &patches);
assert (rc == 0);

assert (streq (path, basedirpath));
freen (path);

if (verbose)
zsys_debug("zdir_test() : removed : zlist_size (patches)=%d",
zlist_size (patches) );
assert (zlist_size (patches) == 1);

patch = (zdir_patch_t *) zlist_pop (patches);
if (verbose)
zsys_debug("zdir_test() : removed : zdir_patch_path (patch)='%s'",
zdir_patch_path (patch) );
assert (streq (zdir_patch_path (patch), basedirpath));

patch_file = zdir_patch_file (patch);
if (verbose)
zsys_debug("zdir_test() : removed : zfile_filename (patch_file, \"\")='%s'",
zfile_filename (patch_file, "") );
assert (streq (zfile_filename (patch_file, ""), filepath2));

zdir_patch_destroy (&patch);
zlist_destroy (&patches);

zpoller_destroy (&watch_poll);
zactor_destroy (&watch);

// clean up by removing the test directory.
dir = zdir_new (basedirpath, NULL);
assert (dir);
zdir_remove (dir, true);
zdir_destroy (&dir);

zstr_free (&basedirpath);
zstr_free (&filepath1);
zstr_free (&filepath2);

#if defined (__WINDOWS__)
zsys_shutdown();
#endif

AUTHORS

The czmq manual was written by the authors in the AUTHORS file.

RESOURCES

Main web site:

Report bugs to the email <zeromq-dev@lists.zeromq.org [1] >

COPYRIGHT

Copyright (c) the Contributors as noted in the AUTHORS file. This file is part of CZMQ, the high-level C binding for 0MQ: http://czmq.zeromq.org. This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0. If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/. LICENSE included with the czmq distribution.

NOTES

1.

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