fix bug; simplify code

README.md

@@ -11,16 +11,16 @@ Performance
 capacity=200M, 64 bytes key/value tests, tested on (Xeon E5-2670 0 @ 2.60GHz, 128GB ram)
 
 * hashtable.c (raw hash table in c, tested on `malloc`ed memory)
-    set: 0.93 Million iops
-    get: 2.35 Million iops
+> set: 0.93 Million iops
+> get: 2.35 Million iops
 
 * HashTable.py (simple wrapper)
-    set: 250k iops
-    get: 145k iops
+> set: 250k iops
+> get: 145k iops
 
 * Cacher.py (cached wrapper, with serialized)
-    set: 180k iops (write_through), 83k iops (writ_back)
-    get: 135k iops (write_through), 73k iops (writ_back)
+> set: 180k iops (write\_through), 83k iops (writ\_back)
+> get: 135k iops (write\_through), 73k iops (writ\_back)
 
 Notice
 ======

hashtable.c

@@ -50,15 +50,6 @@ static inline void fill_ht_str(ht_str *s, const char *str, const u_int32 size) {
     memcpy(s->str, str, size);
 }
 
-static void dump_ht_str(ht_str *s) {
-    if (s) {
-        printf("%u: %*s\n", s->size, (int)s->size, s->str);
-    }
-    else {
-        printf("(nil)\n");
-    }
-}
-
 static unsigned int ht_get_prime_by(size_t capacity) {
     unsigned i = 0;
     capacity *= 2;
@@ -241,6 +232,17 @@ int ht_destroy(hashtable *ht) {
 }
 
 /*
+
+//commented out together with 'main' to eliminate compiler's complaint
+static void dump_ht_str(ht_str *s) {
+    if (s) {
+        printf("%u: %*s\n", s->size, (int)s->size, s->str);
+    }
+    else {
+        printf("(nil)\n");
+    }
+}
+
 int main() {
     size_t capacity = 500000;
     printf("%u\n", ht_get_prime_by(capacity));

shmht.c

@@ -1,3 +1,5 @@
+#define _LARGEFILE64_SOURCE
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -57,7 +59,6 @@ static PyObject * shmht_open(PyObject *self, PyObject *args)
 {
     int fd = 0;
     size_t mem_size = 0;
-    void *base_addr = NULL;
     hashtable *ht = NULL;
 
     const char *name;
@@ -80,24 +81,30 @@ static PyObject * shmht_open(PyObject *self, PyObject *args)
     if (force_init == 0) { //try to load from existing shmht
         mem_size = sizeof(hashtable);
         if (buf.st_size >= sizeof(hashtable)) { //may be valid
-            base_addr = mmap(NULL, sizeof(hashtable), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
-            if (base_addr == MAP_FAILED) {
+            ht = mmap(NULL, sizeof(hashtable), PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+            if (ht == MAP_FAILED) {
                 PyErr_Format(shmht_error, "mmap failed, map_size=sizeof(hashtable)=%lu: [%d] %s",
                                             mem_size, errno, strerror(errno));
                 goto create_failed;
             }
 
-            if (ht_is_valid((hashtable *)base_addr)) {
-                ht = (hashtable *)base_addr;
+            if (ht_is_valid(ht)) {
                 if (capacity != 0 && capacity != ht->orig_capacity) {
                     PyErr_Format(shmht_error, "please specify the 3rd arg(force_init=1) to overwrite an existing shmht");
                     goto create_failed;
                 }
                 capacity = ht->orig_capacity; //loaded capacity
             }
+            munmap(ht, sizeof(hashtable));
+            ht = NULL;
         }
     }
 
+    if (capacity == 0) {
+        PyErr_Format(shmht_error, "please specify 'capacity' when you try to create a shmht");
+        goto create_failed;
+    }
+
     mem_size = ht_memory_size(capacity);
 
     if (buf.st_size < mem_size) {
@@ -112,29 +119,14 @@ static PyObject * shmht_open(PyObject *self, PyObject *args)
         }
     }
 
-    if (base_addr == NULL) {
-        if (capacity == 0) {
-            PyErr_Format(shmht_error, "please specify 'capacity' when you try to create a shmht");
-            goto create_failed;
-        }
-        base_addr = mmap(NULL, mem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
-        if (base_addr == MAP_FAILED) {
-            PyErr_Format(shmht_error, "mmap failed, mem_size=%lu: [%d] %s",
-                                        mem_size, errno, strerror(errno));
-            goto create_failed;
-        }
-    }
-    else {
-        void *new_base_addr = mremap(base_addr, sizeof(hashtable), mem_size, MREMAP_MAYMOVE);
-        if (new_base_addr == MAP_FAILED) {
-            PyErr_Format(shmht_error, "mremap failed, mem_size=%lu: [%d] %s",
-                                        mem_size, errno, strerror(errno));
-            goto create_failed;
-        }
-        base_addr = new_base_addr;
+    ht = mmap(NULL, mem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
+    if (ht == MAP_FAILED) {
+        PyErr_Format(shmht_error, "mmap failed, mem_size=%lu: [%d] %s",
+                                    mem_size, errno, strerror(errno));
+        goto create_failed;
     }
 
-    ht = ht_init(base_addr, capacity, force_init);
+    ht_init(ht, capacity, force_init);
     int count;
     for (count = 0; count < max_ht_map_entries; count++)
     {
@@ -156,8 +148,8 @@ static PyObject * shmht_open(PyObject *self, PyObject *args)
 create_failed:
     if (fd >= 0)
         close(fd);
-    if (base_addr != NULL)
-        munmap(base_addr, mem_size);
+    if (ht != NULL)
+        munmap(ht, mem_size);
     return NULL;
 }