Merge pull request #50 from JakeRoggenbuck/hash

Hash

src/testing/main.c

@@ -1,11 +1,13 @@
 #include "codegen/x86/test_x86.h"
 #include "lexer/test_lexer.h"
 #include <util/test_list.h>
+#include <util/test_util.h>
 
 int main() {
 	test_lexer();
 	test_x86();
 	test_list();
+	test_util();
 
 	return 0;
 }

src/util/hashmap.c

@@ -0,0 +1,174 @@
+#include "hashmap.h"
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <testing/tassert.h>
+#include <testing/test_utils.h>
+
+unsigned fnva1(char *value) {
+    unsigned long h = 16777619;
+    long int prime = 2166136261;
+
+    while (*value != '\0') {
+        h ^= *value;
+        h *= prime;
+        ++value;
+    }
+
+    return h;
+}
+
+unsigned equal_key(char *a, char *b) { return strcmp(a, b) == 0; }
+
+struct Hashmap *create_hashmap(int capacity) {
+    struct Hashmap *h = malloc(sizeof(struct Hashmap));
+
+    h->buckets = calloc(capacity, sizeof(struct BucketNode *));
+
+    h->size = 0;
+    h->cap = capacity;
+
+    h->hash = fnva1;
+    h->equals = equal_key;
+
+    return h;
+}
+
+void destroy_hashmap(struct Hashmap *h) {
+    free(h->buckets);
+    free(h);
+}
+
+struct BucketNode *create_bucket(char *key, void *value) {
+    struct BucketNode *b = malloc(sizeof(struct BucketNode));
+
+    b->key = key;
+    b->value = value;
+    b->next = NULL;
+
+    return b;
+}
+
+struct BucketNode *hm_get(struct Hashmap *h, char *key) {
+    unsigned a = h->hash(key) % h->cap;
+
+    struct BucketNode *b = h->buckets[a];
+
+    if (b == NULL) {
+        return NULL;
+    }
+
+    if (h->equals(b->key, key)) {
+        return b;
+    }
+
+    // check for linear probing
+
+    return NULL;
+}
+
+int hm_set(struct Hashmap *h, char *key, void *value) {
+    unsigned a = h->hash(key) % h->cap;
+
+    struct BucketNode *b = h->buckets[a];
+
+    if (b == NULL) {
+        if (h->size == h->cap) {
+            double_cap(h);
+        }
+
+        h->size++;
+
+        h->buckets[a] = malloc(sizeof(struct BucketNode *));
+        h->buckets[a]->key = key;
+        h->buckets[a]->value = value;
+        h->buckets[a]->next = NULL;
+
+        return 0;
+    } else {
+        // Handle linear probing
+        return -1;
+    }
+}
+
+void double_cap(struct Hashmap *h) {
+    struct BucketNode **new_buckets =
+        calloc(h->cap * 2, sizeof(struct BucketNode *));
+
+    for (int i = 0; i < h->cap; i++) {
+
+        if (h->buckets[i] != NULL) {
+            struct BucketNode *b = h->buckets[i];
+            unsigned a = h->hash(b->key) % h->cap;
+            new_buckets[a] = b;
+        }
+    }
+
+    h->buckets = new_buckets;
+
+    h->cap = h->cap * 2;
+}
+
+int test_hash_init() {
+    testing_func_setup();
+    struct Hashmap *h = create_hashmap(100);
+
+    tassert(h->size == 0);
+    tassert(h->cap == 100);
+}
+
+int test_hash_init_and_store() {
+    testing_func_setup();
+    struct Hashmap *h = create_hashmap(100);
+
+    tassert(h->size == 0);
+    tassert(h->cap == 100);
+
+    char name[5] = "jake";
+
+    char key[5] = "test";
+    int ret = hm_set(h, key, name);
+    tassert(ret != -1);
+
+    uint64_t ind = h->hash(key) % h->cap;
+    struct BucketNode *b = h->buckets[ind];
+    tassert(strcmp(b->key, key) == 0);
+
+    tassert(h->size == 1);
+    tassert(h->cap == 100);
+}
+
+int test_hash_set_and_get() {
+    testing_func_setup();
+    struct Hashmap *h = create_hashmap(100);
+
+    char name[100] = "jake";
+    char key[10] = "test";
+
+    int ret = hm_set(h, key, name);
+    tassert(ret != -1);
+
+    struct BucketNode *got = hm_get(h, "test");
+    tassert(strcmp(got->value, "jake") == 0);
+
+    return 0;
+}
+
+int test_hash_set_and_double_get() {
+    testing_func_setup();
+    struct Hashmap *h = create_hashmap(100);
+
+    char name[100] = "jake";
+    char key[10] = "test";
+
+    int ret = hm_set(h, key, name);
+    tassert(ret != -1);
+
+    double_cap(h);
+
+    struct BucketNode *got = hm_get(h, "test");
+    tassert(strcmp(got->value, "jake") == 0);
+
+    return 0;
+}

src/util/hashmap.h

@@ -0,0 +1,32 @@
+struct BucketNode {
+    char *key;
+    void *value;
+    struct BucketNode *next;
+};
+
+struct Hashmap {
+    struct BucketNode **buckets;
+    int size;
+    int cap;
+
+    unsigned (*hash)(char *);
+    unsigned (*equals)(char *, char *);
+};
+
+struct Hashmap *create_hashmap(int capacity);
+void destroy_hashmap(struct Hashmap *h);
+
+struct BucketNode *create_bucket(char *key, void *value);
+
+// Get a value with a key
+struct BucketNode *hm_get(struct Hashmap *h, char *key);
+// Set a value with a key
+int hm_set(struct Hashmap *h, char *key, void *value);
+// Double the capacity of the hashmap (happens automatically when size >
+// capacity)
+void double_cap(struct Hashmap *h);
+
+int test_hash_init();
+int test_hash_init_and_store();
+int test_hash_set_and_get();
+int test_hash_set_and_double_get();

src/util/test_util.c

@@ -0,0 +1,14 @@
+#include "hashmap.h"
+#include <testing/test_utils.h>
+
+int test_util() {
+    testing_module_setup();
+
+    test_hash_init();
+    test_hash_init_and_store();
+    test_hash_set_and_get();
+	test_hash_set_and_double_get();
+
+    testing_module_cleanup();
+    return 0;
+}

src/util/test_util.h

@@ -0,0 +1,5 @@
+#pragma once
+
+#include "hashmap.h"
+
+int test_util();