Llewellyn/conky
1
0
Fork 0
mirror of https://github.com/Llewellynvdm/conky.git synced 2024-11-17 10:35:10 +00:00
Code Issues Releases Activity

index processes in a hash table for faster lookup

Browse Source
This commit is contained in:
Phil Sutter 2009-09-20 16:09:18 +02:00
parent 596449c902
commit d163293f66
1 changed files with 81 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

87
src/top.c
View File

@ -36,6 +36,73 @@ static unsigned long g_time = 0;
static unsigned long long previous_total = 0;
static struct process *first_process = 0;
/* a simple hash table to speed up find_process() */
struct proc_hash_entry {
struct proc_hash_entry *next;
struct process *proc;
};
static struct proc_hash_entry proc_hash_table[256];
static void hash_process(struct process *p)
{
struct proc_hash_entry *phe;
static char first_run = 1;
/* better make sure all next pointers are zero upon first access */
if (first_run) {
memset(proc_hash_table, 0, sizeof(struct proc_hash_entry) * 256);
first_run = 0;
}
/* get the bucket head */
phe = &proc_hash_table[p->pid % 256];
/* find the bucket's end */
while (phe->next)
phe = phe->next;
/* append process */
phe->next = malloc(sizeof(struct proc_hash_entry));
memset(phe->next, 0, sizeof(struct proc_hash_entry));
phe->next->proc = p;
}
static void unhash_process(struct process *p)
{
struct proc_hash_entry *phe, *tmp;
/* get the bucket head */
phe = &proc_hash_table[p->pid % 256];
/* find the entry pointing to p and drop it */
while (phe->next) {
if (phe->next->proc == p) {
tmp = phe->next;
phe->next = phe->next->next;
free(tmp);
return;
}
phe = phe->next;
}
}
static void __unhash_all_processes(struct proc_hash_entry *phe)
{
if (phe->next)
__unhash_all_processes(phe->next);
free(phe->next);
}
static void unhash_all_processes(void)
{
int i;
for (i = 0; i < 256; i++) {
__unhash_all_processes(&proc_hash_table[i]);
proc_hash_table[i].next = NULL;
}
}
struct process *get_first_process(void)
{
return first_process;
@ -54,6 +121,9 @@ void free_all_processes(void)
pr = next;
}
first_process = NULL;
/* drop the whole hash table */
unhash_all_processes();
}
struct process *get_process_by_name(const char *name)
@ -70,13 +140,13 @@ struct process *get_process_by_name(const char *name)
static struct process *find_process(pid_t pid)
{
struct process *p = first_process;
struct proc_hash_entry *phe;
while (p) {
if (p->pid == pid) {
return p;
}
p = p->next;
phe = &proc_hash_table[pid % 256];
while (phe->next) {
if (phe->next->proc->pid == pid)
return phe->next->proc;
phe = phe->next;
}
return 0;
}
@ -111,6 +181,9 @@ static struct process *new_process(int p)
/* process_find_name(process); */
/* add the process to the hash table */
hash_process(process);
return process;
}
@ -415,6 +488,8 @@ static void delete_process(struct process *p)
if (p->name) {
free(p->name);
}
/* remove the process from the hash table */
unhash_process(p);
free(p);
}