Some hashtable changes

[xonotic/gmqcc.git] / util.c

diff --git a/util.c b/util.c
index 6d947427cec991f6f659df420c826a03c5430fc0..3065607d970d837e44f236a234a33020aa11af94 100644 (file)
--- a/util.c
+++ b/util.c
@@ -1,6 +1,7 @@
 /*
  * Copyright (C) 2012
  *     Dale Weiler
+ *     Wolfgang Bumiller
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy of
  * this software and associated documentation files (the "Software"), to deal in
@@ -477,44 +478,21 @@ int util_getline(char **lineptr, size_t *n, FILE *stream) {
 
 size_t util_strtocmd(const char *in, char *out, size_t outsz) {
     size_t sz = 1;
-    for (; *in && sz < outsz; ++in, ++out, ++sz) {
-        if (*in == '-')
-            *out = '_';
-        else if (isalpha(*in) && !isupper(*in))
-            *out = *in + 'A' - 'a';
-        else
-            *out = *in;
-    }
+    for (; *in && sz < outsz; ++in, ++out, ++sz)
+        *out = (*in == '-') ? '_' : (isalpha(*in) && !isupper(*in)) ? *in + 'A' - 'a': *in;
     *out = 0;
     return sz-1;
 }
 
 size_t util_strtononcmd(const char *in, char *out, size_t outsz) {
     size_t sz = 1;
-    for (; *in && sz < outsz; ++in, ++out, ++sz) {
-        if (*in == '_')
-            *out = '-';
-        else if (isalpha(*in) && isupper(*in))
-            *out = *in + 'a' - 'A';
-        else
-            *out = *in;
-            
-        *out = (isalpha(*in) && isupper(*in)) ? *in + 'a' - 'A' : *in;
-    }
+    for (; *in && sz < outsz; ++in, ++out, ++sz)
+        *out = (*in == '_') ? '-' : (isalpha(*in) && isupper(*in)) ? *in + 'a' - 'A' : *in;
     *out = 0;
     return sz-1;
 }
 
 
-bool util_filexists(const char *file) {
-    FILE *fp = fopen(file, "rb");
-    if  (!fp) return false;
-    
-    /* it exists */
-    fclose(fp);
-    return true;
-}
-
 FILE *util_fopen(const char *filename, const char *mode)
 {
 #ifdef WIN32
@@ -535,3 +513,138 @@ void _util_vec_grow(void **a, size_t i, size_t s) {
     *a = (void*)((size_t*)p + 2);
     _vec_beg(*a) = m;
 }
+
+/*
+ * Hash table for generic data, based on dynamic memory allocations
+ * all around.  This is the internal interface, please look for
+ * EXPOSED INTERFACE comment below
+ */
+typedef struct hash_node_t {
+    char               *key;   /* the key for this node in table */
+    void               *value; /* pointer to the data as void*   */
+    struct hash_node_t *next;  /* next node (linked list)        */
+} hash_node_t;
+
+
+size_t _util_hthash(hash_table_t *ht, const char *key) {
+    uint64_t val = 0;
+    size_t   len = strlen(key);
+    size_t   itr = 0;
+    
+    
+    while (val < ((uint64_t)~1) /* MAX SIZE OF UINT64 */ && itr < len) {
+        val  = val << 8;
+        val += key[itr];
+        
+        itr++;
+    }
+    
+    return val % ht->size;
+}
+
+hash_node_t *_util_htnewpair(const char *key, void *value) {
+    hash_node_t *node;
+    if (!(node = mem_a(sizeof(hash_node_t))))
+        return NULL;
+        
+    if (!(node->key = util_strdup(key))) {
+        mem_d(node);
+        return NULL;
+    }
+    
+    node->value = value;
+    node->next  = NULL;
+    
+    return node;
+}
+
+/*
+ * EXPOSED INTERFACE for the hashtable implementation
+ * util_htnew(size)                             -- to make a new hashtable
+ * util_htset(table, key, value, sizeof(value)) -- to set something in the table
+ * util_htget(table, key)                       -- to get something from the table
+ * util_htdel(table)                            -- to delete the table
+ */
+hash_table_t *util_htnew(size_t size) {
+    hash_table_t *hashtable = NULL;
+    if (size < 1)
+        return NULL;
+        
+    if (!(hashtable = mem_a(sizeof(hash_table_t))))
+        return NULL;
+        
+    if (!(hashtable->table = mem_a(sizeof(hash_node_t*) * size))) {
+        mem_d(hashtable);
+        return NULL;
+    }
+    
+    hashtable->size = size;
+    memset(hashtable->table, 0, sizeof(hash_node_t*) * size);
+    
+    return hashtable;
+}
+
+void util_htset(hash_table_t *ht, const char *key, void *value) {
+    size_t bin = 0;
+    hash_node_t *newnode = NULL;
+    hash_node_t *next    = NULL;
+    hash_node_t *last    = NULL;
+    
+    bin  = _util_hthash(ht, key);
+    next = ht->table[bin];
+    
+    while (next && next->key && strcmp(key, next->key) > 0)
+        last = next, next = next->next;
+    
+    /* already in table, do a replace */
+    if (next && next->key && !strcmp(key, next->key) == 0) {
+        next->value = value;
+    } else {
+        /* not found, grow a pair man :P */
+        newnode = _util_htnewpair(key, value);
+        if (next == ht->table[bin]) {
+            newnode->next  = next;
+            ht->table[bin] = newnode;
+        } else if (!next) {
+            last->next = newnode;
+        } else {
+            newnode->next = next;
+            last->next = newnode;
+        }
+    }
+}
+
+void *util_htget(hash_table_t *ht, const char *key) {
+    size_t       bin  = _util_hthash(ht, key);
+    hash_node_t *pair = ht->table[bin];
+    
+    while (pair && pair->key && strcmp(key, pair->key) > 0)
+        pair = pair->next;
+        
+    if (!pair || !pair->key || strcmp(key, pair->key) != 0)
+        return NULL;
+        
+    return pair->value;
+}
+
+/*
+ * Free all allocated data in a hashtable, this is quite the amount
+ * of work.
+ */
+void util_htdel(hash_table_t *ht) {
+    size_t i = 0;
+    for (; i < ht->size; i++) {
+        hash_node_t *n = ht->table[i];
+        
+        /* free in list */
+        while (n) {
+            if (n->key)
+                mem_d(n->key);
+            n = n->next;
+        }
+        
+    }
+    /* free table */
+    mem_d(ht->table);
+    mem_d(ht);
+}