From fcdcd40e955d2958e9616ae2ecd2d97910aba9b1 Mon Sep 17 00:00:00 2001
From: Nathan Fisher <nfisher.sr@gmail.com>
Date: Thu, 17 Aug 2023 23:26:53 -0400
Subject: [PATCH] Add haggis_linkmap_get_or_add

---
 include/linkmap.h | 19 +++------
 linkmap.c         | 99 ++++++++++++++++++++++++++---------------------
 2 files changed, 60 insertions(+), 58 deletions(-)

diff --git a/include/linkmap.h b/include/linkmap.h
index 5069709..9be4722 100644
--- a/include/linkmap.h
+++ b/include/linkmap.h
@@ -42,28 +42,21 @@
 
 #define HAGGIS_BUCKETS_BASE 64
 
-struct _haggis_link {
-    struct _haggis_link *next;
-    char *path;
-};
-
-typedef struct _haggis_link haggis_link;
-
-typedef struct {
+typedef struct __bucket {
     union {
         ino_t val;
         u8 bytes[sizeof(ino_t)];
-    } *key;
+    } key;
     uint64_t hash;
-    char * target;
-    haggis_link *links;
-} haggis_linkmap_node;
+    char * path;
+    struct __bucket * next;
+} haggis_bucket;
 
 typedef struct {
     pthread_mutex_t *mutex;
     size_t len;
     size_t capacity;
-    haggis_linkmap_node *buckets;
+    haggis_bucket *buckets;
 } haggis_linkmap;
 
 #endif // !HAGGIS_LINKMAP
diff --git a/linkmap.c b/linkmap.c
index 6a4e8cf..a9decb6 100644
--- a/linkmap.c
+++ b/linkmap.c
@@ -32,67 +32,50 @@
 
 #include "linkmap.h"
 #include "haggis_private.h"
+#include <limits.h>
+#include <pthread.h>
 #include <stddef.h>
+#include <stdint.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/stat.h>
 
-haggis_link* haggis_link_init(char* path) {
-    haggis_link *link;
+haggis_bucket* haggis_bucket_init(ino_t inode, uint64_t hash, char * path) {
+    haggis_bucket *bucket;
 
-    link = calloc(1, sizeof(haggis_link));
-    if (link == NULL) return NULL;
-    link->path = path;
-    return link;
+    bucket = calloc(1, sizeof(haggis_bucket));
+    if (bucket == NULL) return NULL;
+    bucket->key.val = inode;
+    bucket->hash = hash;
+    bucket->path = path;
+    return bucket;
 }
 
-void haggis_link_deinit(haggis_link *link) {
-    if (link == NULL)
-        return;
-    if (link->path != NULL)
-        free(link->path);
-    free(link);
-}
-
-int haggis_link_append(haggis_link *head, char *path) {
-    haggis_link *tail;
-
-    tail = haggis_link_init(path);
-    if (tail == NULL) return 2;
-    while (head->next != NULL) {
-        head++;
-    }
-    head->next = tail;
-    return 0;
-}
-
-void haggis_linkmap_node_deinit(haggis_linkmap_node *nod) {
-    haggis_link *current;
-    haggis_link *previous;
-
-    current = nod->links;
-    while (current != NULL) {
-        previous = current;
-        current = current->next;
-        free(previous);
-    }
-    if (nod->key != NULL)
-        free(nod->key);
-    if (nod->target != NULL)
-        free(nod->target);
+void haggis_bucket_deinit(haggis_bucket *nod) {
+    if (nod->path != NULL)
+        free(nod->path);
     free(nod);
 }
 
+void haggis_bucket_append(haggis_bucket *head, haggis_bucket *tail) {
+
+    while (head->next != NULL) {
+        head = head->next;
+    }
+    head->next = tail;
+}
+
 int haggis_linkmap_expand(haggis_linkmap *map) {
-    haggis_linkmap_node *buckets_new;
-    haggis_linkmap_node *buckets_old;
+    haggis_bucket *buckets_new;
+    haggis_bucket *buckets_old;
     size_t i, hash, idx;
 
-    buckets_new = calloc(map->capacity + HAGGIS_BUCKETS_BASE, sizeof(haggis_linkmap_node));
+    buckets_new = calloc(map->capacity + HAGGIS_BUCKETS_BASE, sizeof(haggis_bucket));
     if (buckets_new == NULL)
         return 2;
     for (i = 0; i < map->capacity; i++) {
-        if (&map->buckets[i] != NULL) {
-            hash = hash_fnv1a_64(map->buckets[i].key->bytes, sizeof(ino_t));
+        if (map->buckets[i].key.val != 0) {
+            hash = hash_fnv1a_64(&map->buckets[i].key.bytes[0], sizeof(ino_t));
             map ->capacity += HAGGIS_BUCKETS_BASE;
             idx = map->capacity % hash;
             buckets_new[idx] = map->buckets[i];
@@ -104,3 +87,29 @@ int haggis_linkmap_expand(haggis_linkmap *map) {
     map->capacity += HAGGIS_BUCKETS_BASE;
     return 0;
 }
+
+char* haggis_linkmap_get_or_add(haggis_linkmap *map, ino_t inode, char * path) {
+    union {
+        ino_t val;
+        u8 bytes[sizeof(ino_t)];
+    } key;
+    char * target = NULL;
+    size_t idx, hash;
+
+    pthread_mutex_lock(map->mutex);
+    key.val = inode;
+    hash = hash_fnv1a_64(key.bytes, sizeof(ino_t));
+    idx = map->capacity % hash;
+    if (map->buckets[idx].key.val == 0) {
+        map->buckets[idx].key.val = inode;
+        map->buckets[idx].hash = hash;
+        map->buckets[idx].path = path;
+        pthread_mutex_unlock(map->mutex);
+        return NULL;
+    } else if (map->buckets[idx].key.val == inode) {
+        target = strndup(target, PATH_MAX - 1);
+        pthread_mutex_unlock(map->mutex);
+        return target;
+    }
+    return NULL;
+}