Modules: support for modules native data types.

src/modules/hellotype.c

@@ -0,0 +1,221 @@
+#include "../redismodule.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include <stdint.h>
+
+static RedisModuleType *HelloType;
+
+/* ========================== Internal data structure  =======================
+ * This is just a linked list of 64 bit integers where elements are inserted
+ * in-place, so it's ordered. There is no pop/push operation but just insert
+ * because it is enough to show the implementation of new data types without
+ * making things complex. */
+
+struct HelloTypeNode {
+    int64_t value;
+    struct HelloTypeNode *next;
+};
+
+struct HelloTypeObject {
+    struct HelloTypeNode *head;
+    size_t len; /* Number of elements added. */
+};
+
+struct HelloTypeObject *createHelloTypeObject(void) {
+    struct HelloTypeObject *o;
+    o = RedisModule_Alloc(sizeof(*o));
+    o->head = NULL;
+    o->len = 0;
+    return o;
+}
+
+void HelloTypeInsert(struct HelloTypeObject *o, int64_t ele) {
+    struct HelloTypeNode *next = o->head, *newnode, *prev = NULL;
+
+    while(next && next->value < ele) {
+        prev = next;
+        next = next->next;
+    }
+    newnode = RedisModule_Alloc(sizeof(*newnode));
+    newnode->value = ele;
+    newnode->next = next;
+    if (prev) {
+        prev->next = newnode;
+    } else {
+        o->head = newnode;
+    }
+    o->len++;
+}
+
+void HelloTypeReleaseObject(struct HelloTypeObject *o) {
+    struct HelloTypeNode *cur, *next;
+    cur = o->head;
+    while(cur) {
+        next = cur->next;
+        RedisModule_Free(cur);
+        cur = next;
+    }
+    RedisModule_Free(o);
+}
+
+/* ========================= "hellotype" type commands ======================= */
+
+/* HELLOTYPE.INSERT key value */
+int HelloTypeInsert_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+
+    if (argc != 3) return RedisModule_WrongArity(ctx);
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    int type = RedisModule_KeyType(key);
+    if (type != REDISMODULE_KEYTYPE_EMPTY &&
+        RedisModule_ModuleTypeGetType(key) != HelloType)
+    {
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    long long value;
+    if ((RedisModule_StringToLongLong(argv[2],&value) != REDISMODULE_OK)) {
+        return RedisModule_ReplyWithError(ctx,"ERR invalid value: must be a signed 64 bit integer");
+    }
+
+    /* Create an empty value object if the key is currently empty. */
+    struct HelloTypeObject *hto;
+    if (type == REDISMODULE_KEYTYPE_EMPTY) {
+        hto = createHelloTypeObject();
+        RedisModule_ModuleTypeSetValue(key,HelloType,hto);
+    } else {
+        hto = RedisModule_ModuleTypeGetValue(key);
+    }
+
+    /* Insert the new element. */
+    HelloTypeInsert(hto,value);
+
+    RedisModule_ReplyWithLongLong(ctx,hto->len);
+    RedisModule_ReplicateVerbatim(ctx);
+    return REDISMODULE_OK;
+}
+
+/* HELLOTYPE.RANGE key first count */
+int HelloTypeRange_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+
+    if (argc != 4) return RedisModule_WrongArity(ctx);
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    int type = RedisModule_KeyType(key);
+    if (type != REDISMODULE_KEYTYPE_EMPTY &&
+        RedisModule_ModuleTypeGetType(key) != HelloType)
+    {
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    long long first, count;
+    if (RedisModule_StringToLongLong(argv[2],&first) != REDISMODULE_OK ||
+        RedisModule_StringToLongLong(argv[3],&count) != REDISMODULE_OK ||
+        first < 0 || count < 0)
+    {
+        return RedisModule_ReplyWithError(ctx,
+            "ERR invalid first or count parameters");
+    }
+
+    struct HelloTypeObject *hto = RedisModule_ModuleTypeGetValue(key);
+    struct HelloTypeNode *node = hto ? hto->head : NULL;
+    RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN);
+    long long arraylen = 0;
+    while(node && count--) {
+        RedisModule_ReplyWithLongLong(ctx,node->value);
+        arraylen++;
+        node = node->next;
+    }
+    RedisModule_ReplySetArrayLength(ctx,arraylen);
+    return REDISMODULE_OK;
+}
+
+/* HELLOTYPE.LEN key */
+int HelloTypeLen_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    RedisModule_AutoMemory(ctx); /* Use automatic memory management. */
+
+    if (argc != 2) return RedisModule_WrongArity(ctx);
+    RedisModuleKey *key = RedisModule_OpenKey(ctx,argv[1],
+        REDISMODULE_READ|REDISMODULE_WRITE);
+    int type = RedisModule_KeyType(key);
+    if (type != REDISMODULE_KEYTYPE_EMPTY &&
+        RedisModule_ModuleTypeGetType(key) != HelloType)
+    {
+        return RedisModule_ReplyWithError(ctx,REDISMODULE_ERRORMSG_WRONGTYPE);
+    }
+
+    struct HelloTypeObject *hto = RedisModule_ModuleTypeGetValue(key);
+    RedisModule_ReplyWithLongLong(ctx,hto ? hto->len : 0);
+    return REDISMODULE_OK;
+}
+
+
+/* ========================== "hellotype" type methods ======================= */
+
+void *HelloTypeRdbLoad(RedisModuleIO *rdb, int encver) {
+    if (encver != 0) {
+        /* RedisModule_Log("warning","Can't load data with version %d", encver);*/
+        return NULL;
+    }
+    uint64_t elements = RedisModule_LoadUnsigned(rdb);
+    struct HelloTypeObject *hto = createHelloTypeObject();
+    while(elements--) {
+        int64_t ele = RedisModule_LoadSigned(rdb);
+        HelloTypeInsert(hto,ele);
+    }
+    return hto;
+}
+
+void HelloTypeRdbSave(RedisModuleIO *rdb, void *value) {
+    struct HelloTypeObject *hto = value;
+    struct HelloTypeNode *node = hto->head;
+    RedisModule_SaveUnsigned(rdb,hto->len);
+    while(node) {
+        RedisModule_SaveSigned(rdb,node->value);
+        node = node->next;
+    }
+}
+
+void HelloTypeAofRewrite(RedisModuleIO *aof, RedisModuleString *key, void *value) {
+    struct HelloTypeObject *hto = value;
+    struct HelloTypeNode *node = hto->head;
+    while(node) {
+        RedisModule_EmitAOF(aof,"HELLOTYPE.INSERT","sl",key,node->value);
+        node = node->next;
+    }
+}
+
+void HelloTypeDigest(RedisModuleDigest *digest, void *value) {
+}
+
+void HelloTypeFree(void *value) {
+    HelloTypeReleaseObject(value);
+}
+
+/* This function must be present on each Redis module. It is used in order to
+ * register the commands into the Redis server. */
+int RedisModule_OnLoad(RedisModuleCtx *ctx) {
+    if (RedisModule_Init(ctx,"hellotype",1,REDISMODULE_APIVER_1)
+        == REDISMODULE_ERR) return REDISMODULE_ERR;
+
+    HelloType = RedisModule_CreateDataType(ctx,"hellotype",0,HelloTypeRdbLoad,HelloTypeRdbSave,HelloTypeAofRewrite,HelloTypeDigest,HelloTypeFree);
+    if (HelloType == NULL) return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hellotype.insert",
+        HelloTypeInsert_RedisCommand,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hellotype.range",
+        HelloTypeRange_RedisCommand,"readonly",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hellotype.len",
+        HelloTypeLen_RedisCommand,"readonly",1,1,1) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    return REDISMODULE_OK;
+}