diff options
| -rw-r--r-- | plugins/samples/CMakeLists.txt | 9 | ||||
| -rw-r--r-- | plugins/samples/tic-tac-toe.c | 518 |
2 files changed, 527 insertions, 0 deletions
diff --git a/plugins/samples/CMakeLists.txt b/plugins/samples/CMakeLists.txt index 271fb850..9f600c82 100644 --- a/plugins/samples/CMakeLists.txt +++ b/plugins/samples/CMakeLists.txt @@ -27,3 +27,12 @@ SET_TARGET_PROPERTIES(clientCtx-api PROPERTIES TARGET_LINK_LIBRARIES(clientCtx-api ${link_libraries}) INSTALL(TARGETS clientCtx-api LIBRARY DESTINATION ${plugin_install_dir}) + +ADD_LIBRARY(tic-tac-toe MODULE tic-tac-toe.c) +SET_TARGET_PROPERTIES(tic-tac-toe PROPERTIES + PREFIX "" + LINK_FLAGS "-Wl,--version-script=${CMAKE_CURRENT_SOURCE_DIR}/export.map" +) +TARGET_LINK_LIBRARIES(tic-tac-toe ${link_libraries}) +INSTALL(TARGETS tic-tac-toe + LIBRARY DESTINATION ${plugin_install_dir}) diff --git a/plugins/samples/tic-tac-toe.c b/plugins/samples/tic-tac-toe.c new file mode 100644 index 00000000..81349e25 --- /dev/null +++ b/plugins/samples/tic-tac-toe.c @@ -0,0 +1,518 @@ +/* + * Copyright (C) 2016 "IoT.bzh" + * Author José Bollo <jose.bollo@iot.bzh> + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#define _GNU_SOURCE +#include <stdio.h> +#include <string.h> +#include <json-c/json.h> + +#include <afb/afb-plugin.h> + +/* + * the interface to afb-daemon + */ +const struct AFB_interface *afbitf; + +/* + * definition of a board + */ +struct board +{ + struct board *next; + int refcount; + int moves; + int history[9]; + int id; + int level; + char board[9]; +}; + +/* + * list of boards + */ +static struct board *all_boards; + +/* + * Search a board + */ +static struct board *search_board(int id) +{ + struct board *board = all_boards; + while (board != NULL && board->id != id) + board = board->next; + return board; +} + +/* + * Creates a new board + */ +static struct board *get_new_board() +{ + struct board *board = calloc(1, sizeof *board); + memset(board->board, ' ', sizeof board->board); + board->refcount = 1; + board->level = 1; + board->moves = 0; + do { + board->id = (rand() >> 2) % 1000; + } while(board->id == 0 || search_board(board->id) != NULL); + board->next = all_boards; + all_boards = board; + return board; +} + +/* + * Release a board + */ +static void release_board(struct board *board) +{ + /* decrease the reference count ... */ + if (--board->refcount == 0) { + /* ... no more use */ + /* unlink from the list of boards */ + struct board **prv = &all_boards; + while (*prv != NULL && *prv != board) + prv = &(*prv)->next; + if (*prv != NULL) + *prv = board->next; + /* release the used memory */ + free(board); + } +} + +/* + * Checks who wins + * Returns zero if there is no winner + * Returns the char of the winner if a player won + */ +static char winner(const char b[9]) +{ + int i; + char c; + + /* check diagonals */ + c = b[4]; + if (c != ' ') { + if (b[0] == c && b[8] == c) + return c; + if (b[2] == c && b[6] == c) + return c; + } + + /* check lines */ + for (i = 0 ; i <= 6 ; i += 3) { + c = b[i]; + if (c != ' ' && b[i+1] == c && b[i+2] == c) + return c; + } + + /* check columns */ + for (i = 0 ; i <= 2 ; i++) { + c = b[i]; + if (c != ' ' && b[i+3] == c && b[i+6] == c) + return c; + } + + return 0; +} + +/* get the color (X or 0) of the move of index 'move' */ +static char color(int move) +{ + return (move & 1) == 0 ? 'X' : '0'; +} + +/* adds the move to the board */ +static void add_move(struct board *board, int index) +{ + int imove = board->moves++; + board->history[imove] = index; + board->board[index] = color(imove); +} + +/* get a random possible move index from the board described by 'b' */ +static int get_random_move(char b[9]) +{ + int index = rand() % 9; + while (b[index] != ' ') + index = (index + 1) % 9; + return index; +} + +/* + * Scores the position described by 'b' + * for the player of color 'c' using an analysis of 'depth'. + * Returns 1 if player 'c' will win. + * Returns -1 if opponent of player 'c' will win. + * returns 0 otherwise. + */ +static int score_position(char b[9], char c, int depth) +{ + int i, t, r; + + /* check if winner */ + if (winner(b) == c) + return 1; + + /* when depth of analysis is reached return unknown case */ + if (--depth == 0) + return 0; + + /* switch to the opponent */ + c = (char)('O' + 'X' - c); + + /* inspect opponent moves */ + r = 1; + for (i = 0 ; i < 9 ; i++) { + if (b[i] == ' ') { + b[i] = c; + t = score_position(b, c, depth); + b[i] = ' '; + if (t > 0) + return -1; /* opponent will win */ + + if (t == 0) + r = 0; /* something not clear */ + } + } + return r; +} + +/* get one move: return the computed index of the move */ +static int get_move(struct board *board) +{ + int index, depth, t, f; + char c; + char b[9]; + + /* compute the depth */ + depth = board->level - 1; + if (board->moves + depth > 9) + depth = 9 - board->moves; + + /* case of null depth */ + if (depth == 0) + return get_random_move(board->board); + + /* depth and more */ + memcpy(b, board->board, 9); + c = color(board->moves); + f = 0; + for (index = 0 ; index < 9 ; index++) { + if (board->board[index] == ' ') { + board->board[index] = c; + t = score_position(board->board, c, depth); + board->board[index] = ' '; + if (t > 0) + return index; + if (t < 0) + b[index] = '+'; + else + f = 1; + } + } + return get_random_move(f ? b : board->board); +} + +/* + * get the board description + */ +static struct json_object *describe(struct board *board) +{ + int i; + char w; + struct json_object *resu, *arr; + + resu = json_object_new_object(); + + json_object_object_add(resu, "boardid", json_object_new_int(board->id)); + json_object_object_add(resu, "level", json_object_new_int(board->level)); + + arr = json_object_new_array(); + json_object_object_add(resu, "board", arr); + for (i = 0 ; i < 9 ; i++) + json_object_array_add(arr, + json_object_new_string_len(&board->board[i], 1)); + + arr = json_object_new_array(); + json_object_object_add(resu, "history", arr); + for (i = 0 ; i < board->moves ; i++) + json_object_array_add(arr, json_object_new_int(board->history[i])); + + w = winner(board->board); + if (w) + json_object_object_add(resu, "winner", json_object_new_string_len(&w, 1)); + else if (board->moves == 9) + json_object_object_add(resu, "winner", json_object_new_string("none")); + + return resu; +} + +/* + * signals a change of the board + */ +static void changed(struct board *board, const char *reason) +{ + /* TODO */ + WARNING(afbitf, "changed is unimplmented (reason was %s)", reason); +} + +/* + * retrieves the board of the request + */ +static struct board *board_of_req(struct afb_req req) +{ + return afb_req_context(req, (void*)get_new_board, (void*)release_board); +} + +/* + * start a new game + */ +static void new(struct afb_req req) +{ + struct board *board; + + /* retrieves the context for the session */ + board = board_of_req(req); + + /* reset the game */ + memset(board->board, ' ', sizeof board->board); + board->moves = 0; + + /* replies */ + afb_req_success(req, NULL, NULL); + + /* signal change */ + changed(board, "new"); +} + +/* + * get the board + */ +static void board(struct afb_req req) +{ + afb_req_success(req, describe(board_of_req(req)), NULL); +} + +/* + * move a piece + */ +static void move(struct afb_req req) +{ + struct board *board; + int i; + const char *index; + + /* retrieves the context for the session */ + board = board_of_req(req); + + /* retrieves the parameters of the move */ + index = afb_req_value(req, "index"); + i = index == NULL ? -1 : atoi(index); + + /* checks validity of parameters */ + if (i < 0 || i > 8) { + afb_req_fail(req, "error", "bad request"); + return; + } + + /* checks validity of the state */ + if (winner(board->board) != 0) { + afb_req_fail(req, "error", "game terminated"); + return; + } + + /* checks validity of the move */ + if (board->board[i] != ' ') { + afb_req_fail(req, "error", "occupied"); + return; + } + + /* applies the move */ + add_move(board, i); + + /* replies */ + afb_req_success(req, NULL, NULL); + + /* signals change */ + changed(board, "move"); +} + +/* + * set the level + */ +static void level(struct afb_req req) +{ + struct board *board; + int l; + const char *level; + + /* retrieves the context for the session */ + board = board_of_req(req); + + /* retrieves the parameters */ + level = afb_req_value(req, "level"); + l = level == NULL ? -1 : atoi(level); + + /* check validity of parameters */ + if (l < 1 || l > 10) { + afb_req_fail(req, "error", "bad request"); + return; + } + board->level = l; + + /* replies */ + afb_req_success(req, NULL, NULL); + + /* signals change */ + changed(board, "level"); +} + +/* + * Join a board + */ +static void join(struct afb_req req) +{ + struct board *board; + const char *id; + + /* retrieves the context for the session */ + board = board_of_req(req); + + /* retrieves the parameters */ + board = board_of_req(req); + id = afb_req_value(req, "boardid"); + if (id == NULL) + goto bad_request; + + /* check validity of parameters */ + if (strcmp(id, "none")) { + board = get_new_board(); + goto success; + } + board = search_board(atoi(id)); + if (board == NULL) + goto bad_request; + + board->refcount++; +success: + afb_req_context_set(req, board, (void*)release_board); + + /* replies */ + afb_req_success(req, NULL, NULL); + return; + +bad_request: + afb_req_fail(req, "error", "bad request"); + return; +} + +/* + * Undo the last move + */ +static void undo(struct afb_req req) +{ + struct board *board; + int i; + + /* retrieves the context for the session */ + board = board_of_req(req); + + /* checks the state */ + if (board->moves == 0) { + afb_req_fail(req, "error", "bad request"); + return; + } + + /* undo the last move */ + i = board->history[--board->moves]; + board->board[i] = ' '; + + /* replies */ + afb_req_success(req, NULL, NULL); + + /* signals change */ + changed(board, "undo"); +} + +/* + * computer plays + */ +static void play(struct afb_req req) +{ + struct board *board; + int index; + + /* retrieves the context for the session */ + board = board_of_req(req); + + /* checks validity of the state */ + if (winner(board->board) != 0 || board->moves == 9) { + afb_req_fail(req, "error", "game terminated"); + return; + } + + /* gets the move and plays it */ + index = get_move(board); + add_move(board, index); + + /* replies */ + afb_req_success(req, describe(board), NULL); + + /* signals change */ + changed(board, "play"); +} + +/* + * array of the verbs exported to afb-daemon + */ +static const struct AFB_verb_desc_v1 verbs[] = { + /* VERB'S NAME SESSION MANAGEMENT FUNCTION TO CALL SHORT DESCRIPTION */ + { .name= "new", .session= AFB_SESSION_NONE, .callback= new, .info= "Starts a new game" }, + { .name= "play", .session= AFB_SESSION_NONE, .callback= play, .info= "Tells the server to play" }, + { .name= "move", .session= AFB_SESSION_NONE, .callback= move, .info= "Tells the client move" }, + { .name= "board", .session= AFB_SESSION_NONE, .callback= board, .info= "Get the current board" }, + { .name= "level", .session= AFB_SESSION_NONE, .callback= level, .info= "Set the server level" }, + { .name= "join", .session= AFB_SESSION_NONE, .callback= join, .info= "Join a board" }, + { .name= "undo", .session= AFB_SESSION_NONE, .callback= undo, .info= "Undo the last move" }, + /* marker for end of the array */ + { .name= NULL } +}; + +/* + * description of the plugin for afb-daemon + */ +static const struct AFB_plugin plugin_description = +{ + /* description conforms to VERSION 1 */ + .type= AFB_PLUGIN_VERSION_1, + .v1= { /* fills the v1 field of the union when AFB_PLUGIN_VERSION_1 */ + .prefix= "tictactoe", /* the API name (or plugin name or prefix) */ + .info= "Sample tac-tac-toe game", /* short description of of the plugin */ + .verbs = verbs /* the array describing the verbs of the API */ + } +}; + +/* + * activation function for registering the plugin called by afb-daemon + */ +const struct AFB_plugin *pluginAfbV1Register(const struct AFB_interface *itf) +{ + afbitf = itf; // records the interface for accessing afb-daemon + return &plugin_description; // returns the description of the plugin +} + |