GUACAMOLE-313: Use binary search to find human-readable names for known keys.

This commit is contained in:
Michael Jumper 2017-11-26 18:54:59 -08:00
parent df29735c83
commit 3633af5e41

View File

@ -22,11 +22,106 @@
#include "log.h"
#include <stdio.h>
#include <stdlib.h>
/**
* A mapping of X11 keysym to its corresponding human-readable name.
*/
typedef struct guaclog_known_key {
/**
* The X11 keysym of the key.
*/
const int keysym;
/**
* A human-readable name for the key.
*/
const char* name;
} guaclog_known_key;
/**
* All known keys.
*/
const guaclog_known_key known_keys[] = {
{ 0xFFE1, "Shift" }
};
/**
* Comparator for the standard bsearch() function which compares an integer
* keysym against the keysym associated with a guaclog_known_key.
*
* @param key
* The key value being compared against the member. This MUST be the
* keysym value, passed through typecasting to an intptr_t (NOT a pointer
* to the int itself).
*
* @param member
* The member within the known_keys array being compared against the given
* key.
*
* @return
* Zero if the given keysym is equal to that of the given member, a
* positive value if the given keysym is greater than that of the given
* member, or a negative value if the given keysym is less than that of the
* given member.
*/
static int guaclog_known_key_bsearch_compare(const void* key,
const void* member) {
int keysym = (int) ((intptr_t) key);
guaclog_known_key* current = (guaclog_known_key*) member;
/* Compare given keysym to keysym of current member */
return keysym - current->keysym;
}
/**
* Searches through the known_keys array of known keys for the name of the key
* having the given keysym. If found, the name of the keysym is copied into the
* given buffer, which must be at least GUACLOG_MAX_KEY_NAME_LENGTH bytes long.
*
* @param key_name
* The buffer to copy the key name into, which must be at least
* GUACLOG_MAX_KEY_NAME_LENGTH.
*
* @param keysym
* The X11 keysym of the key whose name should be stored in
* key_name.
*
* @return
* The length of the name, in bytes, excluding null terminator, or zero if
* the key could not be found.
*/
static int guaclog_locate_key_name(char* key_name, int keysym) {
/* Search through known keys for given keysym */
guaclog_known_key* found = bsearch((void*) ((intptr_t) keysym),
known_keys, sizeof(known_keys) / sizeof(known_keys[0]),
sizeof(known_keys[0]), guaclog_known_key_bsearch_compare);
/* If found, format name and return length of result */
if (found != NULL)
return snprintf(key_name, GUACLOG_MAX_KEY_NAME_LENGTH,
"[ %s ]", found->name);
/* Key not found */
return 0;
}
int guaclog_key_name(char* key_name, int keysym) {
int name_length;
/* Search for name within list of known keys */
name_length = guaclog_locate_key_name(key_name, keysym);
/* Fallback to using hex keysym as name */
int name_length = snprintf(key_name, GUACLOG_MAX_KEY_NAME_LENGTH,
if (name_length == 0)
name_length = snprintf(key_name, GUACLOG_MAX_KEY_NAME_LENGTH,
"0x%X", keysym);
/* Truncate name if necessary */