From: David Lamparter Date: Fri, 16 Dec 2016 22:27:39 +0000 (+0100) Subject: lib: parser: rewrite token deduplication X-Git-Tag: frr-3.0-branchpoint~33^2~6 X-Git-Url: https://git.puffer.fish/?a=commitdiff_plain;h=de8f7a39836a8f121370c1506cc00e3321f284a2;p=mirror%2Ffrr.git lib: parser: rewrite token deduplication Merge the parsed graph into the existing one as a separate step. This makes it possible to merge identical subgraphs, which is used e.g. in bgpd for neighbor names. Signed-off-by: David Lamparter --- diff --git a/lib/command.c b/lib/command.c index 4a84386858..af6e515ce3 100644 --- a/lib/command.c +++ b/lib/command.c @@ -304,6 +304,272 @@ cmd_prompt (enum node_type node) return cnode->prompt; } +static bool +cmd_nodes_link (struct graph_node *from, struct graph_node *to) +{ + for (size_t i = 0; i < vector_active (from->to); i++) + if (vector_slot (from->to, i) == to) + return true; + return false; +} + +static bool cmd_nodes_equal (struct graph_node *ga, struct graph_node *gb); + +/* returns a single node to be excluded as "next" from iteration + * - for JOIN_TKN, never continue back to the FORK_TKN + * - in all other cases, don't try the node itself (in case of "...") + */ +static inline struct graph_node * +cmd_loopstop(struct graph_node *gn) +{ + struct cmd_token *tok = gn->data; + if (tok->type == JOIN_TKN) + return tok->forkjoin; + else + return gn; +} + +static bool +cmd_subgraph_equal (struct graph_node *ga, struct graph_node *gb, + struct graph_node *a_join) +{ + size_t i, j; + struct graph_node *a_fork, *b_fork; + a_fork = cmd_loopstop (ga); + b_fork = cmd_loopstop (gb); + + if (vector_active (ga->to) != vector_active (gb->to)) + return false; + for (i = 0; i < vector_active (ga->to); i++) + { + struct graph_node *cga = vector_slot (ga->to, i); + + for (j = 0; j < vector_active (gb->to); j++) + { + struct graph_node *cgb = vector_slot (gb->to, i); + + if (cga == a_fork && cgb != b_fork) + continue; + if (cga == a_fork && cgb == b_fork) + break; + + if (cmd_nodes_equal (cga, cgb)) + { + if (cga == a_join) + break; + if (cmd_subgraph_equal (cga, cgb, a_join)) + break; + } + } + if (j == vector_active (gb->to)) + return false; + } + return true; +} + +/* deep compare -- for FORK_TKN, the entire subgraph is compared. + * this is what's needed since we're not currently trying to partially + * merge subgraphs */ +static bool +cmd_nodes_equal (struct graph_node *ga, struct graph_node *gb) +{ + struct cmd_token *a = ga->data, *b = gb->data; + + if (a->type != b->type || a->allowrepeat != b->allowrepeat) + return false; + if (a->type < SPECIAL_TKN && strcmp (a->text, b->text)) + return false; + /* one a ..., the other not. */ + if (cmd_nodes_link (ga, ga) != cmd_nodes_link (gb, gb)) + return false; + + switch (a->type) + { + case RANGE_TKN: + return a->min == b->min && a->max == b->max; + + case FORK_TKN: + /* one is keywords, the other just option or selector ... */ + if (cmd_nodes_link (a->forkjoin, ga) != cmd_nodes_link (b->forkjoin, gb)) + return false; + if (cmd_nodes_link (ga, a->forkjoin) != cmd_nodes_link (gb, b->forkjoin)) + return false; + return cmd_subgraph_equal (ga, gb, a->forkjoin); + + default: + return true; + } +} + +static void +cmd_fork_bump_attr (struct graph_node *gn, struct graph_node *join, + u_char attr) +{ + size_t i; + struct cmd_token *tok = gn->data; + struct graph_node *stop = cmd_loopstop (gn); + + tok->attr = attr; + for (i = 0; i < vector_active (gn->to); i++) + { + struct graph_node *next = vector_slot (gn->to, i); + if (next == stop || next == join) + continue; + cmd_fork_bump_attr (next, join, attr); + } +} + +/* move an entire subtree from the temporary graph resulting from + * parse() into the permanent graph for the command node. + * + * this touches rather deeply into the graph code unfortunately. + */ +static void +cmd_reparent_tree (struct graph *fromgraph, struct graph *tograph, + struct graph_node *node) +{ + struct graph_node *stop = cmd_loopstop (node); + size_t i; + + for (i = 0; i < vector_active (fromgraph->nodes); i++) + if (vector_slot (fromgraph->nodes, i) == node) + { + /* agressive iteration punching through subgraphs - may hit some + * nodes twice. reparent only if found on old graph */ + vector_unset (fromgraph->nodes, i); + vector_set (tograph->nodes, node); + break; + } + + for (i = 0; i < vector_active (node->to); i++) + { + struct graph_node *next = vector_slot (node->to, i); + if (next != stop) + cmd_reparent_tree (fromgraph, tograph, next); + } +} + +static void +cmd_free_recur (struct graph *graph, struct graph_node *node, + struct graph_node *stop) +{ + struct graph_node *next, *nstop; + + for (size_t i = vector_active (node->to); i; i--) + { + next = vector_slot (node->to, i - 1); + if (next == stop) + continue; + nstop = cmd_loopstop (next); + if (nstop != next) + cmd_free_recur (graph, next, nstop); + cmd_free_recur (graph, nstop, stop); + } + graph_delete_node (graph, node); +} + +static void +cmd_free_node (struct graph *graph, struct graph_node *node) +{ + struct cmd_token *tok = node->data; + if (tok->type == JOIN_TKN) + cmd_free_recur (graph, tok->forkjoin, node); + graph_delete_node (graph, node); +} + +/* recursive graph merge. call with + * old ~= new + * (which holds true for old == START_TKN, new == START_TKN) + */ +static void +cmd_merge_nodes (struct graph *oldgraph, struct graph *newgraph, + struct graph_node *old, struct graph_node *new, + int direction) +{ + struct cmd_token *tok; + struct graph_node *old_skip, *new_skip; + old_skip = cmd_loopstop (old); + new_skip = cmd_loopstop (new); + + assert (direction == 1 || direction == -1); + + tok = old->data; + tok->refcnt += direction; + + size_t j, i; + for (j = 0; j < vector_active (new->to); j++) + { + struct graph_node *cnew = vector_slot (new->to, j); + if (cnew == new_skip) + continue; + + for (i = 0; i < vector_active (old->to); i++) + { + struct graph_node *cold = vector_slot (old->to, i); + if (cold == old_skip) + continue; + + if (cmd_nodes_equal (cold, cnew)) + { + struct cmd_token *told = cold->data, *tnew = cnew->data; + + if (told->type == END_TKN) + { + if (direction < 0) + { + graph_delete_node (oldgraph, vector_slot (cold->to, 0)); + graph_delete_node (oldgraph, cold); + } + else + /* force no-match handling to install END_TKN */ + i = vector_active (old->to); + break; + } + + /* the entire fork compared as equal, we continue after it. */ + if (told->type == FORK_TKN) + { + if (tnew->attr < told->attr && direction > 0) + cmd_fork_bump_attr (cold, told->forkjoin, tnew->attr); + /* XXX: no reverse bump on uninstall */ + told = (cold = told->forkjoin)->data; + tnew = (cnew = tnew->forkjoin)->data; + } + if (tnew->attr < told->attr) + told->attr = tnew->attr; + + cmd_merge_nodes (oldgraph, newgraph, cold, cnew, direction); + break; + } + } + /* nothing found => add new to old */ + if (i == vector_active (old->to) && direction > 0) + { + assert (vector_count (cnew->from) == + cmd_nodes_link (cnew, cnew) ? 2 : 1); + graph_remove_edge (new, cnew); + + cmd_reparent_tree (newgraph, oldgraph, cnew); + + graph_add_edge (old, cnew); + } + } + + if (!tok->refcnt) + cmd_free_node (oldgraph, old); +} + +void +cmd_merge_graphs (struct graph *old, struct graph *new, int direction) +{ + assert (vector_active (old->nodes) >= 1); + assert (vector_active (new->nodes) >= 1); + + cmd_merge_nodes (old, new, + vector_slot (old->nodes, 0), vector_slot (new->nodes, 0), + direction); +} + /* Install a command into a node. */ void install_element (enum node_type ntype, struct cmd_element *cmd) @@ -337,13 +603,65 @@ install_element (enum node_type ntype, struct cmd_element *cmd) assert (hash_get (cnode->cmd_hash, cmd, hash_alloc_intern)); - command_parse_format (cnode->cmdgraph, cmd); + struct graph *graph = graph_new(); + struct cmd_token *token = new_cmd_token (START_TKN, CMD_ATTR_NORMAL, NULL, NULL); + graph_new_node (graph, token, (void (*)(void *)) &del_cmd_token); + + command_parse_format (graph, cmd); + cmd_merge_graphs (cnode->cmdgraph, graph, +1); + graph_delete_graph (graph); + vector_set (cnode->cmd_vector, cmd); if (ntype == VIEW_NODE) install_element (ENABLE_NODE, cmd); } +void +uninstall_element (enum node_type ntype, struct cmd_element *cmd) +{ + struct cmd_node *cnode; + + /* cmd_init hasn't been called */ + if (!cmdvec) + { + fprintf (stderr, "%s called before cmd_init, breakage likely\n", + __func__); + return; + } + + cnode = vector_slot (cmdvec, ntype); + + if (cnode == NULL) + { + fprintf (stderr, "Command node %d doesn't exist, please check it\n", + ntype); + exit (EXIT_FAILURE); + } + + if (hash_release (cnode->cmd_hash, cmd) == NULL) + { + fprintf (stderr, + "Trying to uninstall non-installed command (node %d):\n%s\n", + ntype, cmd->string); + return; + } + + vector_unset_value (cnode->cmd_vector, cmd); + + struct graph *graph = graph_new(); + struct cmd_token *token = new_cmd_token (START_TKN, CMD_ATTR_NORMAL, NULL, NULL); + graph_new_node (graph, token, (void (*)(void *)) &del_cmd_token); + + command_parse_format (graph, cmd); + cmd_merge_graphs (cnode->cmdgraph, graph, -1); + graph_delete_graph (graph); + + if (ntype == VIEW_NODE) + uninstall_element (ENABLE_NODE, cmd); +} + + static const unsigned char itoa64[] = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"; @@ -2417,6 +2735,7 @@ new_cmd_token (enum cmd_token_type type, u_char attr, token->attr = attr; token->text = text ? XSTRDUP (MTYPE_CMD_TEXT, text) : NULL; token->desc = desc ? XSTRDUP (MTYPE_CMD_DESC, desc) : NULL; + token->refcnt = 1; token->arg = NULL; token->allowrepeat = false; diff --git a/lib/command.h b/lib/command.h index 04bba9e412..7986c676fc 100644 --- a/lib/command.h +++ b/lib/command.h @@ -200,6 +200,7 @@ struct cmd_token enum cmd_token_type type; // token type u_char attr; // token attributes bool allowrepeat; // matcher allowed to match token repetively? + uint32_t refcnt; char *text; // token text char *desc; // token description @@ -402,6 +403,10 @@ extern void install_node (struct cmd_node *, int (*) (struct vty *)); extern void install_default (enum node_type); extern void install_element (enum node_type, struct cmd_element *); +/* known issue with uninstall_element: changes to cmd_token->attr (i.e. + * deprecated/hidden) are not reversed. */ +extern void uninstall_element (enum node_type, struct cmd_element *); + /* Concatenates argv[shift] through argv[argc-1] into a single NUL-terminated string with a space between each element (allocated using XMALLOC(MTYPE_TMP)). Returns NULL if shift >= argc. */ @@ -435,6 +440,7 @@ extern void del_cmd_token (struct cmd_token *); extern struct cmd_token *copy_cmd_token (struct cmd_token *); extern vector completions_to_vec (struct list *completions); +extern void cmd_merge_graphs (struct graph *old, struct graph *new, int direction); extern void command_parse_format (struct graph *graph, struct cmd_element *cmd); /* Export typical functions. */ diff --git a/lib/grammar_sandbox.c b/lib/grammar_sandbox.c index 315bd4d59c..0779f23060 100644 --- a/lib/grammar_sandbox.c +++ b/lib/grammar_sandbox.c @@ -68,7 +68,12 @@ DEFUN (grammar_test, cmd->func = NULL; // parse the command and install it into the command graph - command_parse_format (nodegraph, cmd); + struct graph *graph = graph_new(); + struct cmd_token *token = new_cmd_token (START_TKN, CMD_ATTR_NORMAL, NULL, NULL); + graph_new_node (graph, token, (void (*)(void *)) &del_cmd_token); + + command_parse_format (graph, cmd); + cmd_merge_graphs (nodegraph, graph, +1); return CMD_SUCCESS; }