1/**
2 * @file db_insert.c
3 * Inserting a key-value pair into a DB
4 *
5 * @remark Copyright 2002 OProfile authors
6 * @remark Read the file COPYING
7 *
8 * @author Philippe Elie
9 */
10
11#define _GNU_SOURCE
12
13#include <stdio.h>
14#include <stdlib.h>
15#include <string.h>
16#include <errno.h>
17
18#include "odb.h"
19
20
21static inline int add_node(odb_data_t * data, odb_key_t key, odb_value_t value)
22{
23	odb_index_t new_node;
24	odb_node_t * node;
25	odb_index_t index;
26
27	/* no locking is necessary: iteration interface retrieve data through
28	 * the node_base array, we doesn't increase current_size now but it's
29	 * done by odb_commit_reservation() so the new slot is visible only
30	 * after the increment
31	 */
32	if (data->descr->current_size >= data->descr->size) {
33		if (odb_grow_hashtable(data))
34			return EINVAL;
35	}
36	new_node = data->descr->current_size;
37
38	node = &data->node_base[new_node];
39	node->value = value;
40	node->key = key;
41
42	index = odb_do_hash(data, key);
43	node->next = data->hash_base[index];
44	data->hash_base[index] = new_node;
45
46	/* FIXME: we need wrmb() here */
47	odb_commit_reservation(data);
48
49	return 0;
50}
51
52int odb_update_node(odb_t * odb, odb_key_t key)
53{
54	return odb_update_node_with_offset(odb, key, 1);
55}
56
57int odb_update_node_with_offset(odb_t * odb,
58				odb_key_t key,
59				unsigned long int offset)
60{
61	odb_index_t index;
62	odb_node_t * node;
63	odb_data_t * data;
64
65	data = odb->data;
66	index = data->hash_base[odb_do_hash(data, key)];
67	while (index) {
68		node = &data->node_base[index];
69		if (node->key == key) {
70			if (node->value + offset != 0) {
71				node->value += offset;
72			} else {
73				/* post profile tools must handle overflow */
74				/* FIXME: the tricky way will be just to add
75				 * a goto to jump right before the return
76				 * add_node(), in this way we no longer can
77				 * overflow. It'll work because new node are
78				 * linked at the start of the node list for
79				 * this bucket so this loop will see first a
80				 * non overflowed node if one exist. When we
81				 * grow the hashtable the most recently
82				 * allocated node for this key will be setup
83				 * last, so again it'll be linked at start of
84				 * the list. pp tools looke like ok with this
85				 * change.
86				 *
87				 * This change doesn't involve any file format
88				 * change but perhaps it's a bit hacky to do
89				 * this w/o bumping the sample file format
90				 * version. The drawback of this is the added
91				 * node are additive not multiplicative.
92				 * (multiplicative as if we add more bits to
93				 * store a value)
94				 */
95			}
96			return 0;
97		}
98
99		index = node->next;
100	}
101
102	return add_node(data, key, offset);
103}
104
105
106int odb_add_node(odb_t * odb, odb_key_t key, odb_value_t value)
107{
108	return add_node(odb->data, key, value);
109}
110