add python interface

Makefile

@@ -1,5 +1,6 @@
 default: bfilter.c bfilter.h
-	$(CC) -g -DTOK_LIB -Wall -Wextra -std=gnu99 -Wpointer-arith -Wmissing-prototypes -lm -L. -O3 ./bfilter.c -o test --static `pkg-config --libs --cflags libfnv` -Wl,-rpath,/home/wes/bfilter;
+	$(CC) -g -Wall -Wextra -std=gnu99 -Wpointer-arith -Wmissing-prototypes -lm -L. -O3 ./bfilter.c -o test --static `pkg-config --libs --cflags libfnv` -Wl,-rpath,/home/wes/bfilter;
 
-unsafe: bfilter.c  bfilter.h
+lib: bfilter.c bfilter.h
-	$(CC) -DNDEBUG -DTOK_LIB -Wall -std=gnu99 -Wextra -Wpointer-arith -Wmissing-prototypes -lm -L. -O3 ./bfilter.c -o bfilter -Wl,-rpath,/home/wes/bfilter;
+	$(CC) -g -DLIB -c -fpic -Wall -Wextra -pedantic -Wpointer-arith -Werror -std=c99 -lm -L. -O3 ./bfilter.c --static `pkg-config --libs --cflags libfnv` -Wl,-rpath,/home/wes/bfilter;
+	$(CC) -shared -o bfilter.so bfilter.o;

bfilter.c

@@ -7,7 +7,6 @@
 int
 printbits(uint32_t n, size_t c) {
   uint32_t i = c-1;
-
   while (n >= 2) {
     printf("%d", n & 1);
     i--;
@@ -150,7 +149,7 @@ bfilter_set(bit_array_t *filter,
             int k) {
   hashes_t hashes = hash(key, k, filter->num_elems);
 
-  for(int i = 0; i < 5; i++) {
+  for(int i = 0; i < k; i++) {
     setbit(filter, hashes[i]);
   }
   return 0;
@@ -164,7 +163,7 @@ bfilter_get(bit_array_t *filter,
 
   int exists = 1;
 
-  for(int i = 0; i < 5; i++) {
+  for(int i = 0; i < k; i++) {
     if (!getbit(filter, hashes[i])) {
       exists = 0;
     }
@@ -172,6 +171,7 @@ bfilter_get(bit_array_t *filter,
   return exists;
 }
 
+#ifndef LIB
 int
 main (void) {
   bit_array_t *test = empty_bfilter(4000);
@@ -213,3 +213,4 @@ main (void) {
 
   return EXIT_SUCCESS;
 }
+#endif

bfilter.py

@@ -0,0 +1,63 @@
+#! /usr/bin/env python3
+
+from cffi import FFI
+from sys import stdout
+
+ffi = FFI()
+
+lib = ffi.dlopen("./bfilter.so")
+
+ffi.cdef("""
+typedef
+  struct {
+    size_t num_elems;
+    size_t num_ints;
+    uint32_t *arr;
+  }
+  bit_array_t;
+
+typedef
+  struct {
+    uint32_t hash_1;
+    uint32_t hash_2;
+  }
+  fnv_hashes_t;
+
+typedef uint32_t* hashes_t;
+
+int printbits(uint32_t, size_t);
+
+int print_barray(bit_array_t*);
+
+bit_array_t* empty_bfilter(int);
+
+fnv_hashes_t hash_fnv(const char*);
+
+uint32_t kth_hash(fnv_hashes_t, uint32_t, size_t);
+
+hashes_t hash(const char *, uint32_t, size_t);
+
+int setbit(bit_array_t*, int);
+int unsetbit(bit_array_t*, int);
+
+int bfilter_set(bit_array_t *, const char*, int);
+int  bfilter_get(bit_array_t *, const char*, int);
+
+int getbit(bit_array_t *, int);
+""")
+
+bfilter = lib.empty_bfilter(190)
+
+k = 10
+
+with open("./roadnottaken") as rnt:
+    words = rnt.read().split(" ")
+    for word in words:
+        lib.bfilter_set(bfilter, word.encode("UTF-8"), k)
+
+    for word in words:
+        print(lib.bfilter_get(bfilter, word.encode("UTF-8"), k))
+
+    print(lib.bfilter_get(bfilter, b"wes", k))
+
+# lib.print_barray(bfilter)