Add function to add an exiting file to the iso tree.

Node is created using a builder. Default builder and filesystem is added 
to IsoImage. Later we should expose setters for this atts.

src/tree.c

@@ -13,10 +13,14 @@
 #include "libisofs.h"
 #include "node.h"
 #include "error.h"
+#include "image.h"
+#include "fsource.h"
+#include "builder.h"
 
 #include <stdlib.h>
 #include <string.h>
 #include <time.h>
+#include <limits.h>
 
 /**
  * Add a new directory to the iso tree.
@@ -289,3 +293,151 @@ int iso_tree_add_new_special(IsoDir *parent, const char *name, mode_t mode,
     }
     return ++parent->nchildren;
 }
+
+static 
+int iso_tree_add_node_builder(IsoDir *parent, IsoFileSource *src,
+                              IsoNodeBuilder *builder, IsoNode **node)
+{
+    int result;
+    struct stat info;
+    IsoNode *new;
+    IsoNode **pos;
+    char *name;
+    
+    if (parent == NULL || src == NULL || builder == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    if (node) {
+        *node = NULL;
+    }
+    
+    name = src->get_name(src);
+    
+    /* find place where to insert */
+    pos = &(parent->children);
+    while (*pos != NULL && strcmp((*pos)->name, name) < 0) {
+        pos = &((*pos)->next);
+    }
+    if (*pos != NULL && !strcmp((*pos)->name, name)) {
+        /* a node with same name already exists */
+        return ISO_NODE_NAME_NOT_UNIQUE;
+    }
+    
+    /* get info about source */
+    result = src->lstat(src, &info);
+    if (result < 0) {
+        return result;
+    }
+    
+    new = NULL;
+    switch (info.st_mode & S_IFMT) {
+    case S_IFREG:
+        {
+            /* source is a regular file */
+            IsoStream *stream;
+            IsoFile *file;
+            result = iso_file_source_stream_new(src, &stream);
+            if (result < 0) {
+                return result;
+            }
+            file = malloc(sizeof(IsoFile));
+            if (file == NULL) {
+                iso_stream_unref(stream);
+                return ISO_MEM_ERROR;
+            }
+            file->msblock = 0;
+            file->sort_weight = 0;
+            file->stream = stream;
+            file->node.type = LIBISO_FILE;
+            new = (IsoNode*) file;
+        }
+        break;
+    case S_IFDIR:
+        {
+            /* source is a directory */
+            new = calloc(1, sizeof(IsoDir));
+            if (new == NULL) {
+                return ISO_MEM_ERROR;
+            }
+            new->type = LIBISO_DIR;
+        }
+        break;
+    case S_IFLNK:
+        {
+            /* source is a symbolic link */
+            char dest[PATH_MAX];
+            IsoSymlink *link;
+            
+            result = src->readlink(src, dest, PATH_MAX);
+            if (result < 0) {
+                return result;
+            }
+            link = malloc(sizeof(IsoSymlink));
+            if (link == NULL) {
+                return ISO_MEM_ERROR;
+            }
+            link->dest = strdup(dest);
+            link->node.type = LIBISO_SYMLINK;
+            new = (IsoNode*) link;
+        }
+        break;
+    case S_IFSOCK:
+    case S_IFBLK:
+    case S_IFCHR:
+    case S_IFIFO:
+        {
+            /* source is an special file */
+            IsoSpecial *special;
+            special = malloc(sizeof(IsoSpecial));
+            if (special == NULL) {
+                return ISO_MEM_ERROR;
+            }
+            special->dev = info.st_rdev;
+            special->node.type = LIBISO_SPECIAL;
+            new = (IsoNode*) special;
+        }
+        break;
+    }
+    
+    /* fill fields */
+    new->refcount = 1;
+    new->name = strdup(name);
+    new->mode = info.st_mode;
+    new->uid = info.st_uid;
+    new->gid = info.st_gid;
+    new->atime = info.st_atime;
+    new->mtime = info.st_mtime;
+    new->ctime = info.st_ctime;
+    
+    new->hidden = 0;
+    
+    /* finally, add node to parent */
+    new->parent = parent;
+    new->next = *pos;
+    *pos = new;
+    
+    if (node) {
+        *node = new;
+    }
+    return ++parent->nchildren;
+}
+
+int iso_tree_add_node(IsoImage *image, IsoDir *parent, const char *path, 
+                      IsoNode **node)
+{
+    int result;
+    IsoFilesystem *fs;
+    IsoFileSource *file;
+    
+    if (image == NULL || parent == NULL || path == NULL) {
+        return ISO_NULL_POINTER;
+    }
+    
+    fs = image->fs;
+    result = fs->get_by_path(fs, path, &file);
+    if (result < 0) {
+        return result;
+    }
+    result = iso_tree_add_node_builder(parent, file, image->builder, node);
+    return result;
+}