Add checksum computation to rio.c

src/rdb.c

@@ -717,7 +717,7 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
     size_t len;
     unsigned int i;
 
-    redisLog(REDIS_DEBUG,"LOADING OBJECT %d (at %d)\n",rdbtype,rdb->tell(rdb));
+    redisLog(REDIS_DEBUG,"LOADING OBJECT %d (at %d)\n",rdbtype,rdbTell(rdb));
     if (rdbtype == REDIS_RDB_TYPE_STRING) {
         /* Read string value */
         if ((o = rdbLoadEncodedStringObject(rdb)) == NULL) return NULL;
@@ -1039,7 +1039,7 @@ int rdbLoad(char *filename) {
 
         /* Serve the clients from time to time */
         if (!(loops++ % 1000)) {
-            loadingProgress(rdb.tell(&rdb));
+            loadingProgress(rdbTell(&rdb));
             aeProcessEvents(server.el, AE_FILE_EVENTS|AE_DONT_WAIT);
         }
 

src/rio.c

@@ -58,6 +58,8 @@ static const rio rioBufferIO = {
     rioBufferRead,
     rioBufferWrite,
     rioBufferTell,
+    NULL,           /* update_checksum */
+    0,              /* current checksum */
     { { NULL, 0 } } /* union for io-specific vars */
 };
 
@@ -65,6 +67,8 @@ static const rio rioFileIO = {
     rioFileRead,
     rioFileWrite,
     rioFileTell,
+    NULL,           /* update_checksum */
+    0,              /* current checksum */
     { { NULL, 0 } } /* union for io-specific vars */
 };
 
@@ -79,6 +83,12 @@ void rioInitWithBuffer(rio *r, sds s) {
     r->io.buffer.pos = 0;
 }
 
+/* This function can be installed both in memory and file streams when checksum
+ * computation is needed. */
+void rioGenericUpdateChecksum(rio *r, const void *buf, size_t len) {
+    r->checksum = crc64(r->checksum,buf,len);
+}
+
 /* ------------------------------ Higher level interface ---------------------------
  * The following higher level functions use lower level rio.c functions to help
  * generating the Redis protocol for the Append Only File. */

src/rio.h

@@ -2,6 +2,7 @@
 #define __REDIS_RIO_H
 
 #include <stdio.h>
+#include <stdint.h>
 #include "sds.h"
 
 struct _rio {
@@ -11,6 +12,14 @@ struct _rio {
     size_t (*read)(struct _rio *, void *buf, size_t len);
     size_t (*write)(struct _rio *, const void *buf, size_t len);
     off_t (*tell)(struct _rio *);
+    /* The update_cksum method if not NULL is used to compute the checksum of all the
+     * data that was read or written so far. The method should be designed so that
+     * can be called with the current checksum, and the buf and len fields pointing
+     * to the new block of data to add to the checksum computation. */
+    void (*update_cksum)(struct _rio *, void *buf, size_t len);
+
+    /* The current checksum */
+    uint64_t cksum;
 
     /* Backend-specific vars. */
     union {
@@ -26,8 +35,26 @@ struct _rio {
 
 typedef struct _rio rio;
 
-#define rioWrite(rio,buf,len) ((rio)->write((rio),(buf),(len)))
-#define rioRead(rio,buf,len) ((rio)->read((rio),(buf),(len)))
+/* The following functions are our interface with the stream. They'll call the
+ * actual implementation of read / write / tell, and will update the checksum
+ * if needed. */
+
+inline size_t rioWrite(rio *r, const void *buf, size_t len) {
+    if (r->udpate_cksum) r->update_cksum(r,buf,len);
+    return r->write(r,buf,len);
+}
+
+inline size_t rioRead(rio *r, void *buf, size_t len) {
+    if (r->read(r,buf,len) == 1) {
+        if (r->udpate_cksum) r->update_cksum(r,buf,len);
+        return 1;
+    }
+    return 0;
+}
+
+inline off_t rioTell(rio *r) {
+    return r->tell(r);
+}
 
 void rioInitWithFile(rio *r, FILE *fp);
 void rioInitWithBuffer(rio *r, sds s);
@@ -37,4 +64,6 @@ size_t rioWriteBulkString(rio *r, const char *buf, size_t len);
 size_t rioWriteBulkLongLong(rio *r, long long l);
 size_t rioWriteBulkDouble(rio *r, double d);
 
+void rioGenericUpdateChecksum(rio *r, const void *buf, size_t len);
+
 #endif