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libisofs/src/node.c

551 lines
12 KiB

/*
* Copyright (c) 2007 Vreixo Formoso
*
* This file is part of the libisofs project; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation. See COPYING file for details.
*/
#include "libisofs.h"
#include "node.h"
#include "error.h"
#include "stream.h"
#include <stdlib.h>
#include <string.h>
#include <time.h>
/**
* Increments the reference counting of the given node.
*/
void iso_node_ref(IsoNode *node)
{
++node->refcount;
}
/**
* Decrements the reference couting of the given node.
* If it reach 0, the node is free, and, if the node is a directory,
* its children will be unref() too.
*/
void iso_node_unref(IsoNode *node)
{
if (--node->refcount == 0) {
switch(node->type) {
case LIBISO_DIR:
{
IsoNode *child = ((IsoDir*)node)->children;
while (child != NULL) {
IsoNode *tmp = child->next;
child->parent = NULL;
iso_node_unref(child);
child = tmp;
}
}
break;
case LIBISO_FILE:
{
IsoFile *file = (IsoFile*) node;
iso_stream_unref(file->stream);
}
break;
case LIBISO_SYMLINK:
{
IsoSymlink *link = (IsoSymlink*) node;
free(link->dest);
}
default:
/* TODO #00002 handle deletion of each kind of node */
break;
}
free(node->name);
free(node);
}
}
/**
* Get the type of an IsoNode.
*/
enum IsoNodeType iso_node_get_type(IsoNode *node)
{
return node->type;
}
/**
* Set the name of a node.
*
* @param name The name in UTF-8 encoding
*/
int iso_node_set_name(IsoNode *node, const char *name)
{
char *new;
if (node->parent != NULL) {
/* check if parent already has a node with same name */
if (iso_dir_get_node(node->parent, name, NULL) == 1) {
return ISO_NODE_NAME_NOT_UNIQUE;
}
}
new = strdup(name);
if (new == NULL) {
return ISO_MEM_ERROR;
}
free(node->name);
node->name = new;
if (node->parent != NULL) {
IsoDir *parent;
int res;
/* take and add again to ensure correct children order */
parent = node->parent;
iso_node_take(node);
res = iso_dir_add_node(parent, node, 0);
if (res < 0) {
return res;
}
}
return ISO_SUCCESS;
}
/**
* Get the name of a node (in UTF-8).
* The returned string belongs to the node and should not be modified nor
* freed. Use strdup if you really need your own copy.
*/
const char *iso_node_get_name(const IsoNode *node)
{
return node->name;
}
/**
* Set the permissions for the node. This attribute is only useful when
* Rock Ridge extensions are enabled.
*
* @param mode
* bitmask with the permissions of the node, as specified in 'man 2 stat'.
* The file type bitfields will be ignored, only file permissions will be
* modified.
*/
void iso_node_set_permissions(IsoNode *node, mode_t mode)
{
node->mode = (node->mode & S_IFMT) | (mode & ~S_IFMT);
}
/**
* Get the permissions for the node
*/
mode_t iso_node_get_permissions(const IsoNode *node)
{
return node->mode & ~S_IFMT;
}
/**
* Get the mode of the node, both permissions and file type, as specified in
* 'man 2 stat'.
*/
mode_t iso_node_get_mode(const IsoNode *node)
{
return node->mode;
}
/**
* Set the user id for the node. This attribute is only useful when
* Rock Ridge extensions are enabled.
*/
void iso_node_set_uid(IsoNode *node, uid_t uid)
{
node->uid = uid;
}
/**
* Get the user id of the node.
*/
uid_t iso_node_get_uid(const IsoNode *node)
{
return node->uid;
}
/**
* Set the group id for the node. This attribute is only useful when
* Rock Ridge extensions are enabled.
*/
void iso_node_set_gid(IsoNode *node, gid_t gid)
{
node->gid = gid;
}
/**
* Get the group id of the node.
*/
gid_t iso_node_get_gid(const IsoNode *node)
{
return node->gid;
}
/**
* Set the time of last modification of the file
*/
void iso_node_set_mtime(IsoNode *node, time_t time)
{
node->mtime = time;
}
/**
* Get the time of last modification of the file
*/
time_t iso_node_get_mtime(const IsoNode *node)
{
return node->mtime;
}
/**
* Set the time of last access to the file
*/
void iso_node_set_atime(IsoNode *node, time_t time)
{
node->atime = time;
}
/**
* Get the time of last access to the file
*/
time_t iso_node_get_atime(const IsoNode *node)
{
return node->atime;
}
/**
* Set the time of last status change of the file
*/
void iso_node_set_ctime(IsoNode *node, time_t time)
{
node->ctime = time;
}
/**
* Get the time of last status change of the file
*/
time_t iso_node_get_ctime(const IsoNode *node)
{
return node->ctime;
}
/**
* Add a new node to a dir. Note that this function don't add a new ref to
* the node, so you don't need to free it, it will be automatically freed
* when the dir is deleted. Of course, if you want to keep using the node
* after the dir life, you need to iso_node_ref() it.
*
* @param dir
* the dir where to add the node
* @param child
* the node to add. You must ensure that the node hasn't previously added
* to other dir, and that the node name is unique inside the child.
* Otherwise this function will return a failure, and the child won't be
* inserted.
* @return
* number of nodes in dir if succes, < 0 otherwise
*/
int iso_dir_add_node(IsoDir *dir, IsoNode *child, int replace)
{
IsoNode **pos;
if (dir == NULL || child == NULL) {
return ISO_NULL_POINTER;
}
if ((IsoNode*)dir == child) {
return ISO_WRONG_ARG_VALUE;
}
/*
* check if child is already added to another dir, or if child
* is the root node, where parent == itself
*/
if (child->parent != NULL || child->parent == (IsoDir*)child) {
return ISO_NODE_ALREADY_ADDED;
}
pos = &(dir->children);
while (*pos != NULL && strcmp((*pos)->name, child->name) < 0) {
pos = &((*pos)->next);
}
if (*pos != NULL && !strcmp((*pos)->name, child->name)) {
/* a node with same name already exists */
if (replace == 0) {
return ISO_NODE_NAME_NOT_UNIQUE;
} else if (replace == 1) {
child->next = (*pos)->next;
(*pos)->parent = NULL;
(*pos)->next = NULL;
iso_node_unref(*pos);
*pos = child;
child->parent = dir;
return dir->nchildren;
} else {
return ISO_WRONG_ARG_VALUE;
}
}
child->next = *pos;
*pos = child;
child->parent = dir;
return ++dir->nchildren;
}
/**
* Locate a node inside a given dir.
*
* @param name
* The name of the node
* @param node
* Location for a pointer to the node, it will filled with NULL if the dir
* doesn't have a child with the given name.
* The node will be owned by the dir and shouldn't be unref(). Just call
* iso_node_ref() to get your own reference to the node.
* Note that you can pass NULL is the only thing you want to do is check
* if a node with such name already exists on dir.
* @return
* 1 node found, 0 child has no such node, < 0 error
* Possible errors:
* ISO_NULL_POINTER, if dir or name are NULL
*/
int iso_dir_get_node(IsoDir *dir, const char *name, IsoNode **node)
{
IsoNode *pos;
if (dir == NULL || name == NULL) {
return ISO_NULL_POINTER;
}
pos = dir->children;
while (pos != NULL && strcmp(pos->name, name) < 0) {
pos = pos->next;
}
if (pos == NULL || strcmp(pos->name, name)) {
if (node) {
*node = NULL;
}
return 0; /* node not found */
}
if (node) {
*node = pos;
}
return 1;
}
/**
* Get the number of children of a directory.
*
* @return
* >= 0 number of items, < 0 error
* Possible errors:
* ISO_NULL_POINTER, if dir is NULL
*/
int iso_dir_get_nchildren(IsoDir *dir)
{
if (dir == NULL) {
return ISO_NULL_POINTER;
}
return dir->nchildren;
}
int iso_dir_get_children(const IsoDir *dir, IsoDirIter **iter)
{
IsoDirIter *it;
if (dir == NULL || iter == NULL) {
return ISO_NULL_POINTER;
}
it = malloc(sizeof(IsoDirIter));
if (it == NULL) {
return ISO_OUT_OF_MEM;
}
it->dir = dir;
it->pos = dir->children;
*iter = it;
return ISO_SUCCESS;
}
int iso_dir_iter_next(IsoDirIter *iter, IsoNode **node)
{
IsoNode *n;
if (iter == NULL || node == NULL) {
return ISO_NULL_POINTER;
}
n = iter->pos;
if (n == NULL) {
*node = NULL;
return 0;
}
if (n->parent != iter->dir) {
/* this can happen if the node has been moved to another dir */
return ISO_ERROR;
}
*node = n;
iter->pos = n->next;
return ISO_SUCCESS;
}
/**
* Check if there're more children.
*
* @return
* 1 dir has more elements, 0 no, < 0 error
* Possible errors:
* ISO_NULL_POINTER, if iter is NULL
*/
int iso_dir_iter_has_next(IsoDirIter *iter)
{
if (iter == NULL) {
return ISO_NULL_POINTER;
}
return iter->pos == NULL ? 0 : 1;
}
void iso_dir_iter_free(IsoDirIter *iter)
{
free(iter);
}
static IsoNode**
iso_dir_find_node(IsoDir *dir, IsoNode *node)
{
IsoNode **pos;
pos = &(dir->children);
while (*pos != NULL && *pos != node) {
pos = &((*pos)->next);
}
return pos;
}
/**
* Removes a child from a directory.
* The child is not freed, so you will become the owner of the node. Later
* you can add the node to another dir (calling iso_dir_add_node), or free
* it if you don't need it (with iso_node_unref).
*
* @return
* 1 on success, < 0 error
*/
int iso_node_take(IsoNode *node)
{
IsoNode **pos;
IsoDir* dir;
if (node == NULL) {
return ISO_NULL_POINTER;
}
dir = node->parent;
if (dir == NULL) {
return ISO_NODE_NOT_ADDED_TO_DIR;
}
pos = iso_dir_find_node(dir, node);
if (pos == NULL) {
/* should never occur */
return ISO_ERROR;
}
*pos = node->next;
node->parent = NULL;
node->next = NULL;
dir->nchildren--;
return ISO_SUCCESS;
}
/**
* Removes a child from a directory and free (unref) it.
* If you want to keep the child alive, you need to iso_node_ref() it
* before this call, but in that case iso_node_take() is a better
* alternative.
*
* @return
* 1 on success, < 0 error
*/
int iso_node_remove(IsoNode *node)
{
int ret;
ret = iso_node_take(node);
if (ret == ISO_SUCCESS) {
iso_node_unref(node);
}
return ret;
}
/* TODO #00005 optimize iso_dir_iter_take */
int iso_dir_iter_take(IsoDirIter *iter)
{
IsoNode *pos;
if (iter == NULL) {
return ISO_NULL_POINTER;
}
pos = iter->dir->children;
if (iter->pos == pos) {
return ISO_ERROR;
}
while (pos != NULL && pos->next == iter->pos) {
pos = pos->next;
}
if (pos == NULL) {
return ISO_ERROR;
}
return iso_node_take(pos);
}
int iso_dir_iter_remove(IsoDirIter *iter)
{
IsoNode *pos;
if (iter == NULL) {
return ISO_NULL_POINTER;
}
pos = iter->dir->children;
if (iter->pos == pos) {
return ISO_ERROR;
}
while (pos != NULL && pos->next == iter->pos) {
pos = pos->next;
}
if (pos == NULL) {
return ISO_ERROR;
}
return iso_node_remove(pos);
}
/**
* Get the destination of a node (in UTF-8).
* The returned string belongs to the node and should not be modified nor
* freed. Use strdup if you really need your own copy.
*/
const char *iso_symlink_get_dest(const IsoSymlink *link)
{
return link->dest;
}
/**
* Set the destination of a link.
*/
void iso_symlink_set_dest(IsoSymlink *link, const char *dest)
{
free(link->dest);
link->dest = strdup(dest);
}
int iso_node_new_root(IsoDir **root)
{
IsoDir *dir;
dir = calloc(1, sizeof(IsoDir));
if (dir == NULL) {
return ISO_MEM_ERROR;
}
dir->node.type = LIBISO_DIR;
dir->node.atime = dir->node.ctime = dir->node.mtime = time(NULL);
dir->node.mode = S_IFDIR | 0555;
/* set parent to itself, to prevent root to be added to another dir */
dir->node.parent = dir;
*root = dir;
return ISO_SUCCESS;
}