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mirror of git://projects.qi-hardware.com/wernermisc.git synced 2024-11-27 20:14:03 +02:00
wernermisc/qpkg/id.c
Werner Almesberger dd8bb6eecd qpkg: moved comp_versions from prereq.c to id.c
- id.c: added section titles
- prereq.c (comp_versions), id.h, id.c: moved comp_versions from prereq.c
  to id.c, to allow sharing with other code
2010-11-21 21:14:04 -03:00

147 lines
2.7 KiB
C

/*
* id.c - Registry of unique and alphabetically sorted identifiers
*
* Written 2010 by Werner Almesberger
* Copyright 2010 Werner Almesberger
*
* 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 2 of the License, or
* (at your option) any later version.
*/
#include <string.h>
#include <ctype.h>
#include "jrb.h"
#include "util.h"
#include "id.h"
static struct id *free_id = NULL;
/* ----- ID comparison (regular string compare) ---------------------------- */
static int do_comp_id(const struct id *a, const struct id *b)
{
int len = a->len < b->len ? a->len : b->len;
int cmp;
cmp = memcmp(a->s, b->s, len);
if (cmp)
return cmp;
return a->len < b->len ? -1 : a->len > b->len;
}
int comp_id(const void *a, const void *b)
{
return do_comp_id(a, b);
}
/* ----- Version comparison ------------------------------------------------ */
static int epoch(const char **s, const struct id *id)
{
const char *end = id->s+id->len;
int n = 0;
while (*s != end && isdigit(**s)) {
n = 10*n+**s-'0';
(*s)++;
}
if (*s == id->s || (*s != end && **s == ':'))
return n;
*s = id->s;
return 0;
}
int comp_versions(const struct id *va, const struct id *vb)
{
int epoch_a = 0, epoch_b = 0;
const char *a = va->s;
const char *b = vb->s;
const char *ea = a+va->len;
const char *eb = b+vb->len;
epoch_a = epoch(&a, va);
epoch_b = epoch(&b, vb);
if (epoch_a != epoch_b)
return epoch_a-epoch_b;
while (1) {
if (a == ea || b == eb)
return (a != ea)-(b != eb);
if (isdigit(*a) && isdigit(*b)) {
int na = 0, nb = 0;
while (a != ea && isdigit(*a)) {
na = na*10+*a-'0';
a++;
}
while (b != eb && isdigit(*b)) {
nb = nb*10+*b-'0';
b++;
}
if (na == nb)
continue;
return na-nb;
}
if (*a > *b)
return 1;
if (*a < *b)
return 1;
a++;
b++;
}
}
/* ----- Tree maintenance -------------------------------------------------- */
struct tree *make_tree(int (*comp)(const void *a, const void *b))
{
struct tree *tree;
tree = alloc_type(struct tree);
tree->comp = comp;
tree->root = make_jrb();
return tree;
}
struct jrb *make_id(struct tree *tree, const char *s, size_t len)
{
struct id *id;
if (!free_id)
free_id = alloc_type(struct id);
id = free_id;
id->s = s;
id->len = len;
id->jrb = jrb_find_or_insert(tree->root, id, NULL, tree->comp);
if (id->jrb->key == id)
free_id = NULL;
return id->jrb;
}
const struct jrb *find_id(const struct tree *tree, const char *s, size_t len)
{
struct id id = {
.s = s,
.len = len
};
return jrb_find(tree->root, &id, tree->comp);
}