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Diffstat (limited to 'src/libmdsserver/fd-table.h')
| -rw-r--r-- | src/libmdsserver/fd-table.h | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/src/libmdsserver/fd-table.h b/src/libmdsserver/fd-table.h new file mode 100644 index 0000000..79bd2dc --- /dev/null +++ b/src/libmdsserver/fd-table.h @@ -0,0 +1,177 @@ +/** + * mds — A micro-display server + * Copyright © 2014 Mattias Andrée (maandree@member.fsf.org) + * + * This program is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef MDS_LIBMDSSERVER_FD_TABLE_H +#define MDS_LIBMDSSERVER_FD_TABLE_H + + +#include "table-common.h" + +#include <stdint.h> + + +/** + * Value lookup table optimised for file descriptors as keys + */ +typedef struct fd_table +{ + /** + * The table's capacity, i.e. how many entries that can be stored, + * in total, before its internal table needs to grow + */ + size_t capacity; + + /** + * The number of entries stored in the table + */ + size_t size; + + /** + * Map from keys to values + */ + size_t* values; + + /** + * Map from keys to whether that are in used, bit-packed + */ + uint64_t* used; + + /** + * Check whether two values are equal + * + * If this function pointer is `NULL`, the identity is used + * + * Be aware, this variable cannot be marshalled + */ + compare_func* value_comparator; + +} fd_table_t; + + + +/** + * Create a fd table + * + * @param this Memory slot in which to store the new fd table + * @param initial_capacity The initial capacity of the table + * @return Non-zero on error, `errno` will have been set accordingly + */ +int fd_table_create_tuned(fd_table_t* restrict this, size_t initial_capacity); + +/** + * Create a fd table + * + * @param this:fd_table_t* Memory slot in which to store the new fd table + * @return :int Non-zero on error, `errno` will have been set accordingly + */ +#define fd_table_create(this) \ + fd_table_create_tuned(this, 16) + +/** + * Release all resources in a fd table, should + * be done even if construction fails + * + * @param this The fd table + * @param keys_freer Function that frees a key, `NULL` if keys should not be freed + * @param values_freer Function that frees a value, `NULL` if value should not be freed + */ +void fd_table_destroy(fd_table_t* restrict this, free_func* key_freer, free_func* value_freer); + +/** + * Check whether a value is stored in the table + * + * @param this The fd table + * @param value The value + * @return Whether the value is stored in the table + */ +int fd_table_contains_value(const fd_table_t* restrict this, size_t value) __attribute__((pure)); + +/** + * Check whether a key is used in the table + * + * @param this The fd table + * @param key The key + * @return Whether the key is used + */ +int fd_table_contains_key(const fd_table_t* restrict this, int key) __attribute__((pure)); + +/** + * Look up a value in the table + * + * @param this The fd table + * @param key The key associated with the value + * @return The value associated with the key, 0 if the key was not used + */ +size_t fd_table_get(const fd_table_t* restrict this, int key) __attribute__((pure)); + +/** + * Add an entry to the table + * + * @param this The fd table + * @param key The key of the entry to add + * @param value The value of the entry to add + * @return The previous value associated with the key, 0 if the key was not used. + * 0 will also be returned on error, check the `errno` variable. + */ +size_t fd_table_put(fd_table_t* restrict this, int key, size_t value); + +/** + * Remove an entry in the table + * + * @param this The fd table + * @param key The key of the entry to remove + * @return The previous value associated with the key, 0 if the key was not used + */ +size_t fd_table_remove(fd_table_t* restrict this, int key); + +/** + * Remove all entries in the table + * + * @param this The fd table + */ +void fd_table_clear(fd_table_t* restrict this); + +/** + * Calculate the buffer size need to marshal a fd table + * + * @param this The fd table + * @return The number of bytes to allocate to the output buffer + */ +size_t fd_table_marshal_size(const fd_table_t* restrict this) __attribute__((pure)); + +/** + * Marshals a fd table + * + * @param this The fd table + * @param data Output buffer for the marshalled data + */ +void fd_table_marshal(const fd_table_t* restrict this, char* restrict data); + +/** + * Unmarshals a fd table + * + * @param this Memory slot in which to store the new fd table + * @param data In buffer with the marshalled data + * @param remapper Function that translates values, `NULL` if not translation takes place + * @return Non-zero one error, errno will be set accordingly. + * Destroy the list on error. + */ +int fd_table_unmarshal(fd_table_t* restrict this, char* restrict data, remap_func* remapper); + + +#endif + |