/**
* Find common prefix from the edges of the node.
*
* Some cases of the common prefix:
*
* 1. "/foo/{slug}" vs "/foo/bar" => common prefix = "/foo/"
* 2. "{slug}/hate" vs "{slug}/bar" => common prefix = "{slug}/"
* 2. "/z/{slug}/hate" vs "/z/{slog}/bar" => common prefix = "/z/"
* 3. "{slug:xxx}/hate" vs "{slug:yyy}/bar" => common prefix = ""
* 4. "aaa{slug:xxx}/hate" vs "aab{slug:yyy}/bar" => common prefix = "aa"
* 5. "/foo/{slug}/hate" vs "/fo{slug}/bar" => common prefix = "/fo"
*/
edge * r3_node_find_common_prefix(node *n, const char *path, int path_len, int *prefix_len, char **errstr) {
int i = 0;
int prefix = 0;
*prefix_len = 0;
edge *e = NULL;
for(i = 0 ; i < n->edge_len ; i++ ) {
// ignore all edges with slug
prefix = strndiff( (char*) path, n->edges[i]->pattern, n->edges[i]->pattern_len);
// no common, consider insert a new edge
if ( prefix > 0 ) {
e = n->edges[i];
break;
}
}
// found common prefix edge
if (prefix > 0) {
r3_slug_t *slug;
int ret = 0;
const char *offset = path;
const char *p = path + prefix;
slug = r3_slug_new(path, path_len);
do {
ret = r3_slug_parse(slug, path, path_len, offset, errstr);
// found slug
if (ret == 1) {
// inside slug, backtrace to the begin of the slug
if ( p >= slug->begin && p <= slug->end ) {
prefix = slug->begin - path - 1;
break;
} else if ( p < slug->begin ) {
break;
} else if ( p >= slug->end && p < (path + path_len) ) {
offset = slug->end + 1;
prefix = p - path;
continue;
} else {
break;
}
} else if (ret == -1) {
r3_slug_free(slug);
return NULL;
} else {
break;
}
} while(ret == 1);
// free the slug
r3_slug_free(slug);
}
*prefix_len = prefix;
return e;
}
/**
* Return the last inserted node.
*/
node * r3_tree_insert_pathl_(node *tree, char *path, int path_len, route * route, void * data)
{
node * n = tree;
edge * e = NULL;
/* length of common prefix */
int prefix_len = 0;
for( int i = 0 ; i < n->edge_len ; i++ ) {
prefix_len = strndiff(path, n->edges[i]->pattern, n->edges[i]->pattern_len);
// printf("prefix_len: %d %s vs %s\n", prefix_len, path, n->edges[i]->pattern );
// no common, consider insert a new edge
if ( prefix_len > 0 ) {
e = n->edges[i];
break;
}
}
// branch the edge at correct position (avoid broken slugs)
char *slug_s;
if ( (slug_s = inside_slug(path, path_len, path + prefix_len)) != NULL ) {
prefix_len = slug_s - path;
}
// common prefix not found, insert a new edge for this pattern
if ( prefix_len == 0 ) {
// there are two more slugs, we should break them into several parts
int slug_cnt = slug_count(path, path_len);
if ( slug_cnt > 1 ) {
int slug_len;
char *p = slug_find_placeholder(path, &slug_len);
#ifdef DEBUG
assert(p);
#endif
// find the next one '{', then break there
if(p) {
p = slug_find_placeholder(p + slug_len + 1, NULL);
}
#ifdef DEBUG
assert(p);
#endif
// insert the first one edge, and break at "p"
node * child = r3_tree_create(3);
r3_node_connect(n, zstrndup(path, (int)(p - path)), child);
// and insert the rest part to the child
return r3_tree_insert_pathl_(child, p, path_len - (int)(p - path), route, data);
} else {
if (slug_cnt == 1) {
// there is one slug, let's see if it's optimiz-able by opcode
int slug_len = 0;
char *slug_p = slug_find_placeholder(path, &slug_len);
int slug_pattern_len = 0;
char *slug_pattern = slug_find_pattern(slug_p, &slug_pattern_len);
int opcode = 0;
// if there is a pattern defined.
if (slug_pattern) {
char *cpattern = slug_compile(slug_pattern, slug_pattern_len);
opcode = r3_pattern_to_opcode(cpattern, strlen(cpattern));
zfree(cpattern);
} else {
opcode = OP_EXPECT_NOSLASH;
}
// found opcode
if (opcode) {
// if the slug starts after one+ charactor, for example foo{slug}
node *c1;
if (slug_p > path) {
c1 = r3_tree_create(3);
r3_node_connectl(n, path, slug_p - path, 1, c1); // duplicate
} else {
c1 = n;
}
node * c2 = r3_tree_create(3);
edge * op_edge = r3_node_connectl(c1, slug_p, slug_len , 1, c2);
op_edge->opcode = opcode;
// insert rest
int restlen = (path_len - (slug_p - path)) - slug_len;
if (restlen) {
return r3_tree_insert_pathl_(c2, slug_p + slug_len, restlen, route, data);
}
c2->data = data;
c2->endpoint++;
if (route) {
route->data = data;
r3_node_append_route(c2, route);
}
return c2;
}
}
// only one slug
node * child = r3_tree_create(3);
r3_node_connect(n, zstrndup(path, path_len) , child);
child->data = data;
child->endpoint++;
if (route) {
route->data = data;
r3_node_append_route(child, route);
}
return child;
}
} else if ( prefix_len == e->pattern_len ) { // fully-equal to the pattern of the edge
char * subpath = path + prefix_len;
int subpath_len = path_len - prefix_len;
// there are something more we can insert
if ( subpath_len > 0 ) {
return r3_tree_insert_pathl_(e->child, subpath, subpath_len, route, data);
} else {
// there are no more path to insert
// see if there is an endpoint already
if (e->child->endpoint > 0) {
// XXX: return an error code instead of NULL
return NULL;
}
e->child->endpoint++; // make it as an endpoint
e->child->data = data;
if (route) {
route->data = data;
r3_node_append_route(e->child, route);
}
return e->child;
}
} else if ( prefix_len < e->pattern_len ) {
/* it's partially matched with the pattern,
* we should split the end point and make a branch here...
*/
char * s2 = path + prefix_len;
int s2_len = path_len - prefix_len;
r3_edge_branch(e, prefix_len);
return r3_tree_insert_pathl_(e->child, s2 , s2_len, route , data);
} else {
printf("unexpected route.");
return NULL;
}
return n;
}
/**
* Return the last inserted node.
*/
node * _r3_tree_insert_pathl(node *tree, char *path, int path_len, route * route, void * data)
{
node * n = tree;
edge * e = NULL;
/* length of common prefix */
int prefix_len = 0;
for( int i = 0 ; i < n->edge_len ; i++ ) {
prefix_len = strndiff(path, n->edges[i]->pattern, n->edges[i]->pattern_len);
// printf("prefix_len: %d %s vs %s\n", prefix_len, path, n->edges[i]->pattern );
// no common, consider insert a new edge
if ( prefix_len > 0 ) {
e = n->edges[i];
break;
}
}
// branch the edge at correct position (avoid broken slugs)
char *slug_s;
if ( (slug_s = inside_slug(path, path_len, path + prefix_len)) != NULL ) {
prefix_len = slug_s - path;
}
// common prefix not found, insert a new edge for this pattern
if ( prefix_len == 0 ) {
// there are two more slugs, we should break them into several parts
if ( count_slug(path, path_len) > 1 ) {
char *p = find_slug_placeholder(path, NULL);
#ifdef DEBUG
assert(p);
#endif
// find the next one
p = find_slug_placeholder(p + 1, NULL);
#ifdef DEBUG
assert(p);
#endif
// insert the first one edge, and break at "p"
node * child = r3_tree_create(3);
r3_node_add_child(n, strndup(path, (int)(p - path)), child);
// and insert the rest part to the child
return _r3_tree_insert_pathl(child, p, path_len - (int)(p - path), route, data);
} else {
node * child = r3_tree_create(3);
r3_node_add_child(n, strndup(path, path_len) , child);
// info("edge not found, insert one: %s\n", path);
child->data = data;
child->endpoint++;
if (route) {
route->data = data;
r3_node_append_route(child, route);
}
return child;
}
} else if ( prefix_len == e->pattern_len ) { // fully-equal to the pattern of the edge
char * subpath = path + prefix_len;
int subpath_len = path_len - prefix_len;
// there are something more we can insert
if ( subpath_len > 0 ) {
return _r3_tree_insert_pathl(e->child, subpath, subpath_len, route, data);
} else {
// there are no more path to insert
// see if there is an endpoint already
if (e->child->endpoint) {
// XXX: return an error code instead of NULL
return NULL;
}
e->child->endpoint++; // make it as an endpoint
e->child->data = data;
if (route) {
route->data = data;
r3_node_append_route(e->child, route);
}
return e->child;
}
} else if ( prefix_len < e->pattern_len ) {
// printf("branch the edge prefix_len: %d\n", prefix_len);
/* it's partially matched with the pattern,
* we should split the end point and make a branch here...
*/
char * s2 = path + prefix_len;
int s2_len = path_len - prefix_len;
r3_edge_branch(e, prefix_len);
return _r3_tree_insert_pathl(e->child, s2 , s2_len, route , data);
} else {
printf("unexpected route.");
return NULL;
}
return n;
}
/**
* Return the last inserted node.
*/
node * r3_tree_insert_pathl(node *tree, char *path, int path_len, route * route, void * data)
{
node * n = tree;
edge * e = NULL;
/* length of common prefix */
int offset = 0;
for( int i = 0 ; i < n->edge_len ; i++ ) {
offset = strndiff(path, n->edges[i]->pattern, n->edges[i]->pattern_len);
// printf("offset: %d %s vs %s\n", offset, path, n->edges[i]->pattern );
// no common, consider insert a new edge
if ( offset > 0 ) {
e = n->edges[i];
break;
}
}
// branch the edge at correct position (avoid broken slugs)
char *slug_s = strchr(path, '{');
char *slug_e = strchr(path, '}');
if ( slug_s && slug_e ) {
if ( offset > (slug_s - path) && offset < (slug_e - path) ) {
// break before '{'
offset = slug_s - path;
}
}
if ( offset == 0 ) {
// not found, we should just insert a whole new edge
node * child = r3_tree_create(3);
r3_node_add_child(n, strndup(path, path_len) , child);
info("edge not found, insert one: %s\n", path);
child->data = data;
child->endpoint++;
if (route) {
route->data = data;
r3_node_append_route(child, route);
}
return child;
} else if ( offset == e->pattern_len ) { // fully-equal to the pattern of the edge
char * subpath = path + offset;
int subpath_len = path_len - offset;
// there are something more we can insert
if ( subpath_len > 0 ) {
return r3_tree_insert_pathl(e->child, subpath, subpath_len, route, data);
} else {
// no more path to insert
e->child->endpoint++; // make it as an endpoint
e->child->data = data;
if (route) {
route->data = data;
r3_node_append_route(e->child, route);
}
return e->child;
}
} else if ( offset < e->pattern_len ) {
// printf("branch the edge offset: %d\n", offset);
/* it's partially matched with the pattern,
* we should split the end point and make a branch here...
*/
node *c2; // child 1, child 2
edge *e2; // edge 1, edge 2
char * s2 = path + offset;
int s2_len = 0;
r3_edge_branch(e, offset);
// here is the new edge from.
c2 = r3_tree_create(3);
s2_len = path_len - offset;
e2 = r3_edge_create(strndup(s2, s2_len), s2_len, c2);
// printf("edge right: %s\n", e2->pattern);
r3_node_append_edge(e->child, e2);
char *op = e->pattern;
// truncate the original edge pattern
e->pattern = strndup(e->pattern, offset);
e->pattern_len = offset;
free(op);
// move n->edges to c1
c2->endpoint++;
c2->data = data;
if (route) {
route->data = data;
r3_node_append_route(c2, route);
}
return c2;
} else {
printf("unexpected route.");
return NULL;
}
return n;
}
