Add first version of a bloom filter

src/bloom.c

@@ -1,17 +1,47 @@
 #include "bloom.h"
 #include "ens/storage.h"
 
-int bloom_init() {
-    // TODO lome: implement
-    return 0;
+bloom_filter_t* bloom_init(size_t size) {
+    bloom_filter_t* bloom = k_calloc(1, sizeof(bloom_filter_t));
+    bloom->size = size;
+    bloom->data = k_malloc(size * sizeof(uint8_t));
+    return bloom;
 }
 
-int bloom_add_record(record_t* record) {
-    // TODO lome: implement
-    return 0;
+void bloom_delete(bloom_filter_t* bloom) {
+    if (bloom) {
+        while (bloom->func) {
+            bloom_hash_t* h;
+            h = bloom->func;
+            bloom->func = h->next;
+            k_free(h);
+        }
+        k_free(bloom->data);
+        k_free(bloom);
+    }
 }
 
-int bloom_probably_has_record(record_t* record) {
-    // TODO lome: implement
-    return 0;
+void bloom_add_record(bloom_filter_t* bloom, record_t* record) {
+    bloom_hash_t* h = bloom->func;
+    uint8_t* data = bloom->data;
+    while (h) {
+        uint32_t hash = h->func(record);
+        hash %= bloom->size * 8;
+        data[hash / 8] |= 1 << (hash % 8);
+        h = h->next;
+    }
+}
+
+bool bloom_probably_has_record(bloom_filter_t* bloom, record_t* record) {
+    bloom_hash_t* h = bloom->func;
+    uint8_t* data = bloom->data;
+    while (h) {
+        uint32_t hash = h->func(record);
+        hash %= bloom->size * 8;
+        if ((data[hash / 8] & (1 << (hash % 8))) == 0) {
+            return false;
+        }
+        h = h->next;
+    }
+    return true;
 }

src/bloom.h

@@ -3,15 +3,28 @@
 
 #include "ens/storage.h"
 
+typedef uint32_t (*hash_function)(const void* data);
+
+typedef struct bloom_hash {
+    hash_function func;
+    struct bloom_hash* next;
+} bloom_hash_t;
+
+typedef struct bloom_filter {
+    bloom_hash_t* func;
+    uint8_t* data;
+    size_t size;
+} bloom_filter_t;
+
 /**
  * Initialize the bloom filter on basis of the already registerred records.
  */
-int bloom_init();
+bloom_filter_t* bloom_init(size_t size);
 
 // TODO lome: maybe only use RPI (should be sufficient)
-int bloom_add_record(record_t* record);
+void bloom_add_record(bloom_filter_t* bloom, record_t* record);
 
 // TODO lome: maybe only use RPI (should be sufficient)
-int bloom_probably_has_record(record_t* record);
+bool bloom_probably_has_record(bloom_filter_t* bloom, record_t* record);
 
 #endif

src/contacts.c

@@ -50,7 +50,7 @@ int register_record(record_t* record) {
     if (rc) {
         return rc;
     }
-    rc = bloom_add_record(record);
+    // rc = bloom_add_record(record);
     return rc;
 }
 

src/main.c

@@ -50,7 +50,7 @@ void main(void) {
     setup_test_data();
 #endif
 
-    err = bloom_init();
+    err = bloom_init(1);
     if (err) {
         printk("init bloom failed (err %d)\n", err);
         return;