Adding upstream version 5:7.2.4.upstream/5%7.2.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1139 insertions, 0 deletions

diff --git a/src/functions.c b/src/functions.c
new file mode 100644
index 0000000..c858db9
--- /dev/null
+++ b/src/functions.c
@@ -0,0 +1,1139 @@
+/*
+ * Copyright (c) 2021, Redis Ltd.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "functions.h"
+#include "sds.h"
+#include "dict.h"
+#include "adlist.h"
+#include "atomicvar.h"
+
+#define LOAD_TIMEOUT_MS 500
+
+typedef enum {
+    restorePolicy_Flush, restorePolicy_Append, restorePolicy_Replace
+} restorePolicy;
+
+static size_t engine_cache_memory = 0;
+
+/* Forward declaration */
+static void engineFunctionDispose(dict *d, void *obj);
+static void engineStatsDispose(dict *d, void *obj);
+static void engineLibraryDispose(dict *d, void *obj);
+static int functionsVerifyName(sds name);
+
+typedef struct functionsLibEngineStats {
+    size_t n_lib;
+    size_t n_functions;
+} functionsLibEngineStats;
+
+struct functionsLibCtx {
+    dict *libraries;     /* Library name -> Library object */
+    dict *functions;     /* Function name -> Function object that can be used to run the function */
+    size_t cache_memory; /* Overhead memory (structs, dictionaries, ..) used by all the functions */
+    dict *engines_stats; /* Per engine statistics */
+};
+
+typedef struct functionsLibMataData {
+    sds engine;
+    sds name;
+    sds code;
+} functionsLibMataData;
+
+dictType engineDictType = {
+        dictSdsCaseHash,       /* hash function */
+        dictSdsDup,            /* key dup */
+        NULL,                  /* val dup */
+        dictSdsKeyCaseCompare, /* key compare */
+        dictSdsDestructor,     /* key destructor */
+        NULL,                  /* val destructor */
+        NULL                   /* allow to expand */
+};
+
+dictType functionDictType = {
+        dictSdsCaseHash,      /* hash function */
+        dictSdsDup,           /* key dup */
+        NULL,                 /* val dup */
+        dictSdsKeyCaseCompare,/* key compare */
+        dictSdsDestructor,    /* key destructor */
+        NULL,                 /* val destructor */
+        NULL                  /* allow to expand */
+};
+
+dictType engineStatsDictType = {
+        dictSdsCaseHash,      /* hash function */
+        dictSdsDup,           /* key dup */
+        NULL,                 /* val dup */
+        dictSdsKeyCaseCompare,/* key compare */
+        dictSdsDestructor,    /* key destructor */
+        engineStatsDispose,   /* val destructor */
+        NULL                  /* allow to expand */
+};
+
+dictType libraryFunctionDictType = {
+        dictSdsHash,          /* hash function */
+        dictSdsDup,           /* key dup */
+        NULL,                 /* val dup */
+        dictSdsKeyCompare,    /* key compare */
+        dictSdsDestructor,    /* key destructor */
+        engineFunctionDispose,/* val destructor */
+        NULL                  /* allow to expand */
+};
+
+dictType librariesDictType = {
+        dictSdsHash,          /* hash function */
+        dictSdsDup,           /* key dup */
+        NULL,                 /* val dup */
+        dictSdsKeyCompare,    /* key compare */
+        dictSdsDestructor,    /* key destructor */
+        engineLibraryDispose, /* val destructor */
+        NULL                  /* allow to expand */
+};
+
+/* Dictionary of engines */
+static dict *engines = NULL;
+
+/* Libraries Ctx.
+ * Contains the dictionary that map a library name to library object,
+ * Contains the dictionary that map a function name to function object,
+ * and the cache memory used by all the functions */
+static functionsLibCtx *curr_functions_lib_ctx = NULL;
+
+static size_t functionMallocSize(functionInfo *fi) {
+    return zmalloc_size(fi) + sdsZmallocSize(fi->name)
+            + (fi->desc ? sdsZmallocSize(fi->desc) : 0)
+            + fi->li->ei->engine->get_function_memory_overhead(fi->function);
+}
+
+static size_t libraryMallocSize(functionLibInfo *li) {
+    return zmalloc_size(li) + sdsZmallocSize(li->name)
+            + sdsZmallocSize(li->code);
+}
+
+static void engineStatsDispose(dict *d, void *obj) {
+    UNUSED(d);
+    functionsLibEngineStats *stats = obj;
+    zfree(stats);
+}
+
+/* Dispose function memory */
+static void engineFunctionDispose(dict *d, void *obj) {
+    UNUSED(d);
+    if (!obj) {
+        return;
+    }
+    functionInfo *fi = obj;
+    sdsfree(fi->name);
+    if (fi->desc) {
+        sdsfree(fi->desc);
+    }
+    engine *engine = fi->li->ei->engine;
+    engine->free_function(engine->engine_ctx, fi->function);
+    zfree(fi);
+}
+
+static void engineLibraryFree(functionLibInfo* li) {
+    if (!li) {
+        return;
+    }
+    dictRelease(li->functions);
+    sdsfree(li->name);
+    sdsfree(li->code);
+    zfree(li);
+}
+
+static void engineLibraryDispose(dict *d, void *obj) {
+    UNUSED(d);
+    engineLibraryFree(obj);
+}
+
+/* Clear all the functions from the given library ctx */
+void functionsLibCtxClear(functionsLibCtx *lib_ctx) {
+    dictEmpty(lib_ctx->functions, NULL);
+    dictEmpty(lib_ctx->libraries, NULL);
+    dictIterator *iter = dictGetIterator(lib_ctx->engines_stats);
+    dictEntry *entry = NULL;
+    while ((entry = dictNext(iter))) {
+        functionsLibEngineStats *stats = dictGetVal(entry);
+        stats->n_functions = 0;
+        stats->n_lib = 0;
+    }
+    dictReleaseIterator(iter);
+    curr_functions_lib_ctx->cache_memory = 0;
+}
+
+void functionsLibCtxClearCurrent(int async) {
+    if (async) {
+        functionsLibCtx *old_l_ctx = curr_functions_lib_ctx;
+        curr_functions_lib_ctx = functionsLibCtxCreate();
+        freeFunctionsAsync(old_l_ctx);
+    } else {
+        functionsLibCtxClear(curr_functions_lib_ctx);
+    }
+}
+
+/* Free the given functions ctx */
+void functionsLibCtxFree(functionsLibCtx *functions_lib_ctx) {
+    functionsLibCtxClear(functions_lib_ctx);
+    dictRelease(functions_lib_ctx->functions);
+    dictRelease(functions_lib_ctx->libraries);
+    dictRelease(functions_lib_ctx->engines_stats);
+    zfree(functions_lib_ctx);
+}
+
+/* Swap the current functions ctx with the given one.
+ * Free the old functions ctx. */
+void functionsLibCtxSwapWithCurrent(functionsLibCtx *new_lib_ctx) {
+    functionsLibCtxFree(curr_functions_lib_ctx);
+    curr_functions_lib_ctx = new_lib_ctx;
+}
+
+/* return the current functions ctx */
+functionsLibCtx* functionsLibCtxGetCurrent(void) {
+    return curr_functions_lib_ctx;
+}
+
+/* Create a new functions ctx */
+functionsLibCtx* functionsLibCtxCreate(void) {
+    functionsLibCtx *ret = zmalloc(sizeof(functionsLibCtx));
+    ret->libraries = dictCreate(&librariesDictType);
+    ret->functions = dictCreate(&functionDictType);
+    ret->engines_stats = dictCreate(&engineStatsDictType);
+    dictIterator *iter = dictGetIterator(engines);
+    dictEntry *entry = NULL;
+    while ((entry = dictNext(iter))) {
+        engineInfo *ei = dictGetVal(entry);
+        functionsLibEngineStats *stats = zcalloc(sizeof(*stats));
+        dictAdd(ret->engines_stats, ei->name, stats);
+    }
+    dictReleaseIterator(iter);
+    ret->cache_memory = 0;
+    return ret;
+}
+
+/*
+ * Creating a function inside the given library.
+ * On success, return C_OK.
+ * On error, return C_ERR and set err output parameter with a relevant error message.
+ *
+ * Note: the code assumes 'name' is NULL terminated but not require it to be binary safe.
+ *       the function will verify that the given name is following the naming format
+ *       and return an error if its not.
+ */
+int functionLibCreateFunction(sds name, void *function, functionLibInfo *li, sds desc, uint64_t f_flags, sds *err) {
+    if (functionsVerifyName(name) != C_OK) {
+        *err = sdsnew("Library names can only contain letters, numbers, or underscores(_) and must be at least one character long");
+        return C_ERR;
+    }
+
+    if (dictFetchValue(li->functions, name)) {
+        *err = sdsnew("Function already exists in the library");
+        return C_ERR;
+    }
+
+    functionInfo *fi = zmalloc(sizeof(*fi));
+    *fi = (functionInfo) {
+        .name = name,
+        .function = function,
+        .li = li,
+        .desc = desc,
+        .f_flags = f_flags,
+    };
+
+    int res = dictAdd(li->functions, fi->name, fi);
+    serverAssert(res == DICT_OK);
+
+    return C_OK;
+}
+
+static functionLibInfo* engineLibraryCreate(sds name, engineInfo *ei, sds code) {
+    functionLibInfo *li = zmalloc(sizeof(*li));
+    *li = (functionLibInfo) {
+        .name = sdsdup(name),
+        .functions = dictCreate(&libraryFunctionDictType),
+        .ei = ei,
+        .code = sdsdup(code),
+    };
+    return li;
+}
+
+static void libraryUnlink(functionsLibCtx *lib_ctx, functionLibInfo* li) {
+    dictIterator *iter = dictGetIterator(li->functions);
+    dictEntry *entry = NULL;
+    while ((entry = dictNext(iter))) {
+        functionInfo *fi = dictGetVal(entry);
+        int ret = dictDelete(lib_ctx->functions, fi->name);
+        serverAssert(ret == DICT_OK);
+        lib_ctx->cache_memory -= functionMallocSize(fi);
+    }
+    dictReleaseIterator(iter);
+    entry = dictUnlink(lib_ctx->libraries, li->name);
+    dictSetVal(lib_ctx->libraries, entry, NULL);
+    dictFreeUnlinkedEntry(lib_ctx->libraries, entry);
+    lib_ctx->cache_memory -= libraryMallocSize(li);
+
+    /* update stats */
+    functionsLibEngineStats *stats = dictFetchValue(lib_ctx->engines_stats, li->ei->name);
+    serverAssert(stats);
+    stats->n_lib--;
+    stats->n_functions -= dictSize(li->functions);
+}
+
+static void libraryLink(functionsLibCtx *lib_ctx, functionLibInfo* li) {
+    dictIterator *iter = dictGetIterator(li->functions);
+    dictEntry *entry = NULL;
+    while ((entry = dictNext(iter))) {
+        functionInfo *fi = dictGetVal(entry);
+        dictAdd(lib_ctx->functions, fi->name, fi);
+        lib_ctx->cache_memory += functionMallocSize(fi);
+    }
+    dictReleaseIterator(iter);
+
+    dictAdd(lib_ctx->libraries, li->name, li);
+    lib_ctx->cache_memory += libraryMallocSize(li);
+
+    /* update stats */
+    functionsLibEngineStats *stats = dictFetchValue(lib_ctx->engines_stats, li->ei->name);
+    serverAssert(stats);
+    stats->n_lib++;
+    stats->n_functions += dictSize(li->functions);
+}
+
+/* Takes all libraries from lib_ctx_src and add to lib_ctx_dst.
+ * On collision, if 'replace' argument is true, replace the existing library with the new one.
+ * Otherwise abort and leave 'lib_ctx_dst' and 'lib_ctx_src' untouched.
+ * Return C_OK on success and C_ERR if aborted. If C_ERR is returned, set a relevant
+ * error message on the 'err' out parameter.
+ *  */
+static int libraryJoin(functionsLibCtx *functions_lib_ctx_dst, functionsLibCtx *functions_lib_ctx_src, int replace, sds *err) {
+    int ret = C_ERR;
+    dictIterator *iter = NULL;
+    /* Stores the libraries we need to replace in case a revert is required.
+     * Only initialized when needed */
+    list *old_libraries_list = NULL;
+    dictEntry *entry = NULL;
+    iter = dictGetIterator(functions_lib_ctx_src->libraries);
+    while ((entry = dictNext(iter))) {
+        functionLibInfo *li = dictGetVal(entry);
+        functionLibInfo *old_li = dictFetchValue(functions_lib_ctx_dst->libraries, li->name);
+        if (old_li) {
+            if (!replace) {
+                /* library already exists, failed the restore. */
+                *err = sdscatfmt(sdsempty(), "Library %s already exists", li->name);
+                goto done;
+            } else {
+                if (!old_libraries_list) {
+                    old_libraries_list = listCreate();
+                    listSetFreeMethod(old_libraries_list, (void (*)(void*))engineLibraryFree);
+                }
+                libraryUnlink(functions_lib_ctx_dst, old_li);
+                listAddNodeTail(old_libraries_list, old_li);
+            }
+        }
+    }
+    dictReleaseIterator(iter);
+    iter = NULL;
+
+    /* Make sure no functions collision */
+    iter = dictGetIterator(functions_lib_ctx_src->functions);
+    while ((entry = dictNext(iter))) {
+        functionInfo *fi = dictGetVal(entry);
+        if (dictFetchValue(functions_lib_ctx_dst->functions, fi->name)) {
+            *err = sdscatfmt(sdsempty(), "Function %s already exists", fi->name);
+            goto done;
+        }
+    }
+    dictReleaseIterator(iter);
+    iter = NULL;
+
+    /* No collision, it is safe to link all the new libraries. */
+    iter = dictGetIterator(functions_lib_ctx_src->libraries);
+    while ((entry = dictNext(iter))) {
+        functionLibInfo *li = dictGetVal(entry);
+        libraryLink(functions_lib_ctx_dst, li);
+        dictSetVal(functions_lib_ctx_src->libraries, entry, NULL);
+    }
+    dictReleaseIterator(iter);
+    iter = NULL;
+
+    functionsLibCtxClear(functions_lib_ctx_src);
+    if (old_libraries_list) {
+        listRelease(old_libraries_list);
+        old_libraries_list = NULL;
+    }
+    ret = C_OK;
+
+done:
+    if (iter) dictReleaseIterator(iter);
+    if (old_libraries_list) {
+        /* Link back all libraries on tmp_l_ctx */
+        while (listLength(old_libraries_list) > 0) {
+            listNode *head = listFirst(old_libraries_list);
+            functionLibInfo *li = listNodeValue(head);
+            listNodeValue(head) = NULL;
+            libraryLink(functions_lib_ctx_dst, li);
+            listDelNode(old_libraries_list, head);
+        }
+        listRelease(old_libraries_list);
+    }
+    return ret;
+}
+
+/* Register an engine, should be called once by the engine on startup and give the following:
+ *
+ * - engine_name - name of the engine to register
+ * - engine_ctx - the engine ctx that should be used by Redis to interact with the engine */
+int functionsRegisterEngine(const char *engine_name, engine *engine) {
+    sds engine_name_sds = sdsnew(engine_name);
+    if (dictFetchValue(engines, engine_name_sds)) {
+        serverLog(LL_WARNING, "Same engine was registered twice");
+        sdsfree(engine_name_sds);
+        return C_ERR;
+    }
+
+    client *c = createClient(NULL);
+    c->flags |= (CLIENT_DENY_BLOCKING | CLIENT_SCRIPT);
+    engineInfo *ei = zmalloc(sizeof(*ei));
+    *ei = (engineInfo ) { .name = engine_name_sds, .engine = engine, .c = c,};
+
+    dictAdd(engines, engine_name_sds, ei);
+
+    engine_cache_memory += zmalloc_size(ei) + sdsZmallocSize(ei->name) +
+            zmalloc_size(engine) +
+            engine->get_engine_memory_overhead(engine->engine_ctx);
+
+    return C_OK;
+}
+
+/*
+ * FUNCTION STATS
+ */
+void functionStatsCommand(client *c) {
+    if (scriptIsRunning() && scriptIsEval()) {
+        addReplyErrorObject(c, shared.slowevalerr);
+        return;
+    }
+
+    addReplyMapLen(c, 2);
+
+    addReplyBulkCString(c, "running_script");
+    if (!scriptIsRunning()) {
+        addReplyNull(c);
+    } else {
+        addReplyMapLen(c, 3);
+        addReplyBulkCString(c, "name");
+        addReplyBulkCString(c, scriptCurrFunction());
+        addReplyBulkCString(c, "command");
+        client *script_client = scriptGetCaller();
+        addReplyArrayLen(c, script_client->argc);
+        for (int i = 0 ; i < script_client->argc ; ++i) {
+            addReplyBulkCBuffer(c, script_client->argv[i]->ptr, sdslen(script_client->argv[i]->ptr));
+        }
+        addReplyBulkCString(c, "duration_ms");
+        addReplyLongLong(c, scriptRunDuration());
+    }
+
+    addReplyBulkCString(c, "engines");
+    addReplyMapLen(c, dictSize(engines));
+    dictIterator *iter = dictGetIterator(engines);
+    dictEntry *entry = NULL;
+    while ((entry = dictNext(iter))) {
+        engineInfo *ei = dictGetVal(entry);
+        addReplyBulkCString(c, ei->name);
+        addReplyMapLen(c, 2);
+        functionsLibEngineStats *e_stats = dictFetchValue(curr_functions_lib_ctx->engines_stats, ei->name);
+        addReplyBulkCString(c, "libraries_count");
+        addReplyLongLong(c, e_stats->n_lib);
+        addReplyBulkCString(c, "functions_count");
+        addReplyLongLong(c, e_stats->n_functions);
+    }
+    dictReleaseIterator(iter);
+}
+
+static void functionListReplyFlags(client *c, functionInfo *fi) {
+    /* First count the number of flags we have */
+    int flagcount = 0;
+    for (scriptFlag *flag = scripts_flags_def; flag->str ; ++flag) {
+        if (fi->f_flags & flag->flag) {
+            ++flagcount;
+        }
+    }
+
+    addReplySetLen(c, flagcount);
+
+    for (scriptFlag *flag = scripts_flags_def; flag->str ; ++flag) {
+        if (fi->f_flags & flag->flag) {
+            addReplyStatus(c, flag->str);
+        }
+    }
+}
+
+/*
+ * FUNCTION LIST [LIBRARYNAME PATTERN] [WITHCODE]
+ *
+ * Return general information about all the libraries:
+ * * Library name
+ * * The engine used to run the Library
+ * * Library description
+ * * Functions list
+ * * Library code (if WITHCODE is given)
+ *
+ * It is also possible to given library name pattern using
+ * LIBRARYNAME argument, if given, return only libraries
+ * that matches the given pattern.
+ */
+void functionListCommand(client *c) {
+    int with_code = 0;
+    sds library_name = NULL;
+    for (int i = 2 ; i < c->argc ; ++i) {
+        robj *next_arg = c->argv[i];
+        if (!with_code && !strcasecmp(next_arg->ptr, "withcode")) {
+            with_code = 1;
+            continue;
+        }
+        if (!library_name && !strcasecmp(next_arg->ptr, "libraryname")) {
+            if (i >= c->argc - 1) {
+                addReplyError(c, "library name argument was not given");
+                return;
+            }
+            library_name = c->argv[++i]->ptr;
+            continue;
+        }
+        addReplyErrorSds(c, sdscatfmt(sdsempty(), "Unknown argument %s", next_arg->ptr));
+        return;
+    }
+    size_t reply_len = 0;
+    void *len_ptr = NULL;
+    if (library_name) {
+        len_ptr = addReplyDeferredLen(c);
+    } else {
+        /* If no pattern is asked we know the reply len and we can just set it */
+        addReplyArrayLen(c, dictSize(curr_functions_lib_ctx->libraries));
+    }
+    dictIterator *iter = dictGetIterator(curr_functions_lib_ctx->libraries);
+    dictEntry *entry = NULL;
+    while ((entry = dictNext(iter))) {
+        functionLibInfo *li = dictGetVal(entry);
+        if (library_name) {
+            if (!stringmatchlen(library_name, sdslen(library_name), li->name, sdslen(li->name), 1)) {
+                continue;
+            }
+        }
+        ++reply_len;
+        addReplyMapLen(c, with_code? 4 : 3);
+        addReplyBulkCString(c, "library_name");
+        addReplyBulkCBuffer(c, li->name, sdslen(li->name));
+        addReplyBulkCString(c, "engine");
+        addReplyBulkCBuffer(c, li->ei->name, sdslen(li->ei->name));
+
+        addReplyBulkCString(c, "functions");
+        addReplyArrayLen(c, dictSize(li->functions));
+        dictIterator *functions_iter = dictGetIterator(li->functions);
+        dictEntry *function_entry = NULL;
+        while ((function_entry = dictNext(functions_iter))) {
+            functionInfo *fi = dictGetVal(function_entry);
+            addReplyMapLen(c, 3);
+            addReplyBulkCString(c, "name");
+            addReplyBulkCBuffer(c, fi->name, sdslen(fi->name));
+            addReplyBulkCString(c, "description");
+            if (fi->desc) {
+                addReplyBulkCBuffer(c, fi->desc, sdslen(fi->desc));
+            } else {
+                addReplyNull(c);
+            }
+            addReplyBulkCString(c, "flags");
+            functionListReplyFlags(c, fi);
+        }
+        dictReleaseIterator(functions_iter);
+
+        if (with_code) {
+            addReplyBulkCString(c, "library_code");
+            addReplyBulkCBuffer(c, li->code, sdslen(li->code));
+        }
+    }
+    dictReleaseIterator(iter);
+    if (len_ptr) {
+        setDeferredArrayLen(c, len_ptr, reply_len);
+    }
+}
+
+/*
+ * FUNCTION DELETE <LIBRARY NAME>
+ */
+void functionDeleteCommand(client *c) {
+    robj *function_name = c->argv[2];
+    functionLibInfo *li = dictFetchValue(curr_functions_lib_ctx->libraries, function_name->ptr);
+    if (!li) {
+        addReplyError(c, "Library not found");
+        return;
+    }
+
+    libraryUnlink(curr_functions_lib_ctx, li);
+    engineLibraryFree(li);
+    /* Indicate that the command changed the data so it will be replicated and
+     * counted as a data change (for persistence configuration) */
+    server.dirty++;
+    addReply(c, shared.ok);
+}
+
+/* FUNCTION KILL */
+void functionKillCommand(client *c) {
+    scriptKill(c, 0);
+}
+
+/* Try to extract command flags if we can, returns the modified flags.
+ * Note that it does not guarantee the command arguments are right. */
+uint64_t fcallGetCommandFlags(client *c, uint64_t cmd_flags) {
+    robj *function_name = c->argv[1];
+    c->cur_script = dictFind(curr_functions_lib_ctx->functions, function_name->ptr);
+    if (!c->cur_script)
+        return cmd_flags;
+    functionInfo *fi = dictGetVal(c->cur_script);
+    uint64_t script_flags = fi->f_flags;
+    return scriptFlagsToCmdFlags(cmd_flags, script_flags);
+}
+
+static void fcallCommandGeneric(client *c, int ro) {
+    /* Functions need to be fed to monitors before the commands they execute. */
+    replicationFeedMonitors(c,server.monitors,c->db->id,c->argv,c->argc);
+
+    robj *function_name = c->argv[1];
+    dictEntry *de = c->cur_script;
+    if (!de)
+        de = dictFind(curr_functions_lib_ctx->functions, function_name->ptr);
+    if (!de) {
+        addReplyError(c, "Function not found");
+        return;
+    }
+    functionInfo *fi = dictGetVal(de);
+    engine *engine = fi->li->ei->engine;
+
+    long long numkeys;
+    /* Get the number of arguments that are keys */
+    if (getLongLongFromObject(c->argv[2], &numkeys) != C_OK) {
+        addReplyError(c, "Bad number of keys provided");
+        return;
+    }
+    if (numkeys > (c->argc - 3)) {
+        addReplyError(c, "Number of keys can't be greater than number of args");
+        return;
+    } else if (numkeys < 0) {
+        addReplyError(c, "Number of keys can't be negative");
+        return;
+    }
+
+    scriptRunCtx run_ctx;
+
+    if (scriptPrepareForRun(&run_ctx, fi->li->ei->c, c, fi->name, fi->f_flags, ro) != C_OK)
+        return;
+
+    engine->call(&run_ctx, engine->engine_ctx, fi->function, c->argv + 3, numkeys,
+                 c->argv + 3 + numkeys, c->argc - 3 - numkeys);
+    scriptResetRun(&run_ctx);
+}
+
+/*
+ * FCALL <FUNCTION NAME> nkeys <key1 .. keyn> <arg1 .. argn>
+ */
+void fcallCommand(client *c) {
+    fcallCommandGeneric(c, 0);
+}
+
+/*
+ * FCALL_RO <FUNCTION NAME> nkeys <key1 .. keyn> <arg1 .. argn>
+ */
+void fcallroCommand(client *c) {
+    fcallCommandGeneric(c, 1);
+}
+
+/*
+ * FUNCTION DUMP
+ *
+ * Returns a binary payload representing all the libraries.
+ * Can be loaded using FUNCTION RESTORE
+ *
+ * The payload structure is the same as on RDB. Each library
+ * is saved separately with the following information:
+ * * Library name
+ * * Engine name
+ * * Library description
+ * * Library code
+ * RDB_OPCODE_FUNCTION2 is saved before each library to present
+ * that the payload is a library.
+ * RDB version and crc64 is saved at the end of the payload.
+ * The RDB version is saved for backward compatibility.
+ * crc64 is saved so we can verify the payload content.
+ */
+void functionDumpCommand(client *c) {
+    unsigned char buf[2];
+    uint64_t crc;
+    rio payload;
+    rioInitWithBuffer(&payload, sdsempty());
+
+    rdbSaveFunctions(&payload);
+
+    /* RDB version */
+    buf[0] = RDB_VERSION & 0xff;
+    buf[1] = (RDB_VERSION >> 8) & 0xff;
+    payload.io.buffer.ptr = sdscatlen(payload.io.buffer.ptr, buf, 2);
+
+    /* CRC64 */
+    crc = crc64(0, (unsigned char*) payload.io.buffer.ptr,
+                sdslen(payload.io.buffer.ptr));
+    memrev64ifbe(&crc);
+    payload.io.buffer.ptr = sdscatlen(payload.io.buffer.ptr, &crc, 8);
+
+    addReplyBulkSds(c, payload.io.buffer.ptr);
+}
+
+/*
+ * FUNCTION RESTORE <payload> [FLUSH|APPEND|REPLACE]
+ *
+ * Restore the libraries represented by the give payload.
+ * Restore policy to can be given to control how to handle existing libraries (default APPEND):
+ * * FLUSH: delete all existing libraries.
+ * * APPEND: appends the restored libraries to the existing libraries. On collision, abort.
+ * * REPLACE: appends the restored libraries to the existing libraries.
+ *   On collision, replace the old libraries with the new libraries.
+ */
+void functionRestoreCommand(client *c) {
+    if (c->argc > 4) {
+        addReplySubcommandSyntaxError(c);
+        return;
+    }
+
+    restorePolicy restore_replicy = restorePolicy_Append; /* default policy: APPEND */
+    sds data = c->argv[2]->ptr;
+    size_t data_len = sdslen(data);
+    rio payload;
+    sds err = NULL;
+
+    if (c->argc == 4) {
+        const char *restore_policy_str = c->argv[3]->ptr;
+        if (!strcasecmp(restore_policy_str, "append")) {
+            restore_replicy = restorePolicy_Append;
+        } else if (!strcasecmp(restore_policy_str, "replace")) {
+            restore_replicy = restorePolicy_Replace;
+        } else if (!strcasecmp(restore_policy_str, "flush")) {
+            restore_replicy = restorePolicy_Flush;
+        } else {
+            addReplyError(c, "Wrong restore policy given, value should be either FLUSH, APPEND or REPLACE.");
+            return;
+        }
+    }
+
+    uint16_t rdbver;
+    if (verifyDumpPayload((unsigned char*)data, data_len, &rdbver) != C_OK) {
+        addReplyError(c, "DUMP payload version or checksum are wrong");
+        return;
+    }
+
+    functionsLibCtx *functions_lib_ctx = functionsLibCtxCreate();
+    rioInitWithBuffer(&payload, data);
+
+    /* Read until reaching last 10 bytes that should contain RDB version and checksum. */
+    while (data_len - payload.io.buffer.pos > 10) {
+        int type;
+        if ((type = rdbLoadType(&payload)) == -1) {
+            err = sdsnew("can not read data type");
+            goto load_error;
+        }
+        if (type == RDB_OPCODE_FUNCTION_PRE_GA) {
+            err = sdsnew("Pre-GA function format not supported");
+            goto load_error;
+        }
+        if (type != RDB_OPCODE_FUNCTION2) {
+            err = sdsnew("given type is not a function");
+            goto load_error;
+        }
+        if (rdbFunctionLoad(&payload, rdbver, functions_lib_ctx, RDBFLAGS_NONE, &err) != C_OK) {
+            if (!err) {
+                err = sdsnew("failed loading the given functions payload");
+            }
+            goto load_error;
+        }
+    }
+
+    if (restore_replicy == restorePolicy_Flush) {
+        functionsLibCtxSwapWithCurrent(functions_lib_ctx);
+        functions_lib_ctx = NULL; /* avoid releasing the f_ctx in the end */
+    } else {
+        if (libraryJoin(curr_functions_lib_ctx, functions_lib_ctx, restore_replicy == restorePolicy_Replace, &err) != C_OK) {
+            goto load_error;
+        }
+    }
+
+    /* Indicate that the command changed the data so it will be replicated and
+     * counted as a data change (for persistence configuration) */
+    server.dirty++;
+
+load_error:
+    if (err) {
+        addReplyErrorSds(c, err);
+    } else {
+        addReply(c, shared.ok);
+    }
+    if (functions_lib_ctx) {
+        functionsLibCtxFree(functions_lib_ctx);
+    }
+}
+
+/* FUNCTION FLUSH [ASYNC | SYNC] */
+void functionFlushCommand(client *c) {
+    if (c->argc > 3) {
+        addReplySubcommandSyntaxError(c);
+        return;
+    }
+    int async = 0;
+    if (c->argc == 3 && !strcasecmp(c->argv[2]->ptr,"sync")) {
+        async = 0;
+    } else if (c->argc == 3 && !strcasecmp(c->argv[2]->ptr,"async")) {
+        async = 1;
+    } else if (c->argc == 2) {
+        async = server.lazyfree_lazy_user_flush ? 1 : 0;
+    } else {
+        addReplyError(c,"FUNCTION FLUSH only supports SYNC|ASYNC option");
+        return;
+    }
+
+    functionsLibCtxClearCurrent(async);
+
+    /* Indicate that the command changed the data so it will be replicated and
+     * counted as a data change (for persistence configuration) */
+    server.dirty++;
+    addReply(c,shared.ok);
+}
+
+/* FUNCTION HELP */
+void functionHelpCommand(client *c) {
+    const char *help[] = {
+"LOAD [REPLACE] <FUNCTION CODE>",
+"    Create a new library with the given library name and code.",
+"DELETE <LIBRARY NAME>",
+"    Delete the given library.",
+"LIST [LIBRARYNAME PATTERN] [WITHCODE]",
+"    Return general information on all the libraries:",
+"    * Library name",
+"    * The engine used to run the Library",
+"    * Library description",
+"    * Functions list",
+"    * Library code (if WITHCODE is given)",
+"    It also possible to get only function that matches a pattern using LIBRARYNAME argument.",
+"STATS",
+"    Return information about the current function running:",
+"    * Function name",
+"    * Command used to run the function",
+"    * Duration in MS that the function is running",
+"    If no function is running, return nil",
+"    In addition, returns a list of available engines.",
+"KILL",
+"    Kill the current running function.",
+"FLUSH [ASYNC|SYNC]",
+"    Delete all the libraries.",
+"    When called without the optional mode argument, the behavior is determined by the",
+"    lazyfree-lazy-user-flush configuration directive. Valid modes are:",
+"    * ASYNC: Asynchronously flush the libraries.",
+"    * SYNC: Synchronously flush the libraries.",
+"DUMP",
+"    Return a serialized payload representing the current libraries, can be restored using FUNCTION RESTORE command",
+"RESTORE <PAYLOAD> [FLUSH|APPEND|REPLACE]",
+"    Restore the libraries represented by the given payload, it is possible to give a restore policy to",
+"    control how to handle existing libraries (default APPEND):",
+"    * FLUSH: delete all existing libraries.",
+"    * APPEND: appends the restored libraries to the existing libraries. On collision, abort.",
+"    * REPLACE: appends the restored libraries to the existing libraries, On collision, replace the old",
+"      libraries with the new libraries (notice that even on this option there is a chance of failure",
+"      in case of functions name collision with another library).",
+NULL };
+    addReplyHelp(c, help);
+}
+
+/* Verify that the function name is of the format: [a-zA-Z0-9_][a-zA-Z0-9_]? */
+static int functionsVerifyName(sds name) {
+    if (sdslen(name) == 0) {
+        return C_ERR;
+    }
+    for (size_t i = 0 ; i < sdslen(name) ; ++i) {
+        char curr_char = name[i];
+        if ((curr_char >= 'a' && curr_char <= 'z') ||
+            (curr_char >= 'A' && curr_char <= 'Z') ||
+            (curr_char >= '0' && curr_char <= '9') ||
+            (curr_char == '_'))
+        {
+            continue;
+        }
+        return C_ERR;
+    }
+    return C_OK;
+}
+
+int functionExtractLibMetaData(sds payload, functionsLibMataData *md, sds *err) {
+    sds name = NULL;
+    sds desc = NULL;
+    sds engine = NULL;
+    sds code = NULL;
+    if (strncmp(payload, "#!", 2) != 0) {
+        *err = sdsnew("Missing library metadata");
+        return C_ERR;
+    }
+    char *shebang_end = strchr(payload, '\n');
+    if (shebang_end == NULL) {
+        *err = sdsnew("Invalid library metadata");
+        return C_ERR;
+    }
+    size_t shebang_len = shebang_end - payload;
+    sds shebang = sdsnewlen(payload, shebang_len);
+    int numparts;
+    sds *parts = sdssplitargs(shebang, &numparts);
+    sdsfree(shebang);
+    if (!parts || numparts == 0) {
+        *err = sdsnew("Invalid library metadata");
+        sdsfreesplitres(parts, numparts);
+        return C_ERR;
+    }
+    engine = sdsdup(parts[0]);
+    sdsrange(engine, 2, -1);
+    for (int i = 1 ; i < numparts ; ++i) {
+        sds part = parts[i];
+        if (strncasecmp(part, "name=", 5) == 0) {
+            if (name) {
+                *err = sdscatfmt(sdsempty(), "Invalid metadata value, name argument was given multiple times");
+                goto error;
+            }
+            name = sdsdup(part);
+            sdsrange(name, 5, -1);
+            continue;
+        }
+        *err = sdscatfmt(sdsempty(), "Invalid metadata value given: %s", part);
+        goto error;
+    }
+
+    if (!name) {
+        *err = sdsnew("Library name was not given");
+        goto error;
+    }
+
+    sdsfreesplitres(parts, numparts);
+
+    md->name = name;
+    md->code = sdsnewlen(shebang_end, sdslen(payload) - shebang_len);
+    md->engine = engine;
+
+    return C_OK;
+
+error:
+    if (name) sdsfree(name);
+    if (desc) sdsfree(desc);
+    if (engine) sdsfree(engine);
+    if (code) sdsfree(code);
+    sdsfreesplitres(parts, numparts);
+    return C_ERR;
+}
+
+void functionFreeLibMetaData(functionsLibMataData *md) {
+    if (md->code) sdsfree(md->code);
+    if (md->name) sdsfree(md->name);
+    if (md->engine) sdsfree(md->engine);
+}
+
+/* Compile and save the given library, return the loaded library name on success
+ * and NULL on failure. In case on failure the err out param is set with relevant error message */
+sds functionsCreateWithLibraryCtx(sds code, int replace, sds* err, functionsLibCtx *lib_ctx, size_t timeout) {
+    dictIterator *iter = NULL;
+    dictEntry *entry = NULL;
+    functionLibInfo *new_li = NULL;
+    functionLibInfo *old_li = NULL;
+    functionsLibMataData md = {0};
+    if (functionExtractLibMetaData(code, &md, err) != C_OK) {
+        return NULL;
+    }
+
+    if (functionsVerifyName(md.name)) {
+        *err = sdsnew("Library names can only contain letters, numbers, or underscores(_) and must be at least one character long");
+        goto error;
+    }
+
+    engineInfo *ei = dictFetchValue(engines, md.engine);
+    if (!ei) {
+        *err = sdscatfmt(sdsempty(), "Engine '%S' not found", md.engine);
+        goto error;
+    }
+    engine *engine = ei->engine;
+
+    old_li = dictFetchValue(lib_ctx->libraries, md.name);
+    if (old_li && !replace) {
+        old_li = NULL;
+        *err = sdscatfmt(sdsempty(), "Library '%S' already exists", md.name);
+        goto error;
+    }
+
+    if (old_li) {
+        libraryUnlink(lib_ctx, old_li);
+    }
+
+    new_li = engineLibraryCreate(md.name, ei, code);
+    if (engine->create(engine->engine_ctx, new_li, md.code, timeout, err) != C_OK) {
+        goto error;
+    }
+
+    if (dictSize(new_li->functions) == 0) {
+        *err = sdsnew("No functions registered");
+        goto error;
+    }
+
+    /* Verify no duplicate functions */
+    iter = dictGetIterator(new_li->functions);
+    while ((entry = dictNext(iter))) {
+        functionInfo *fi = dictGetVal(entry);
+        if (dictFetchValue(lib_ctx->functions, fi->name)) {
+            /* functions name collision, abort. */
+            *err = sdscatfmt(sdsempty(), "Function %s already exists", fi->name);
+            goto error;
+        }
+    }
+    dictReleaseIterator(iter);
+    iter = NULL;
+
+    libraryLink(lib_ctx, new_li);
+
+    if (old_li) {
+        engineLibraryFree(old_li);
+    }
+
+    sds loaded_lib_name = md.name;
+    md.name = NULL;
+    functionFreeLibMetaData(&md);
+
+    return loaded_lib_name;
+
+error:
+    if (iter) dictReleaseIterator(iter);
+    if (new_li) engineLibraryFree(new_li);
+    if (old_li) libraryLink(lib_ctx, old_li);
+    functionFreeLibMetaData(&md);
+    return NULL;
+}
+
+/*
+ * FUNCTION LOAD [REPLACE] <LIBRARY CODE>
+ * REPLACE         - optional, replace existing library
+ * LIBRARY CODE    - library code to pass to the engine
+ */
+void functionLoadCommand(client *c) {
+    int replace = 0;
+    int argc_pos = 2;
+    while (argc_pos < c->argc - 1) {
+        robj *next_arg = c->argv[argc_pos++];
+        if (!strcasecmp(next_arg->ptr, "replace")) {
+            replace = 1;
+            continue;
+        }
+        addReplyErrorFormat(c, "Unknown option given: %s", (char*)next_arg->ptr);
+        return;
+    }
+
+    if (argc_pos >= c->argc) {
+        addReplyError(c, "Function code is missing");
+        return;
+    }
+
+    robj *code = c->argv[argc_pos];
+    sds err = NULL;
+    sds library_name = NULL;
+    size_t timeout = LOAD_TIMEOUT_MS;
+    if (mustObeyClient(c)) {
+        timeout = 0;
+    }
+    if (!(library_name = functionsCreateWithLibraryCtx(code->ptr, replace, &err, curr_functions_lib_ctx, timeout)))
+    {
+        addReplyErrorSds(c, err);
+        return;
+    }
+    /* Indicate that the command changed the data so it will be replicated and
+     * counted as a data change (for persistence configuration) */
+    server.dirty++;
+    addReplyBulkSds(c, library_name);
+}
+
+/* Return memory usage of all the engines combine */
+unsigned long functionsMemory(void) {
+    dictIterator *iter = dictGetIterator(engines);
+    dictEntry *entry = NULL;
+    size_t engines_nemory = 0;
+    while ((entry = dictNext(iter))) {
+        engineInfo *ei = dictGetVal(entry);
+        engine *engine = ei->engine;
+        engines_nemory += engine->get_used_memory(engine->engine_ctx);
+    }
+    dictReleaseIterator(iter);
+
+    return engines_nemory;
+}
+
+/* Return memory overhead of all the engines combine */
+unsigned long functionsMemoryOverhead(void) {
+    size_t memory_overhead = dictMemUsage(engines);
+    memory_overhead += dictMemUsage(curr_functions_lib_ctx->functions);
+    memory_overhead += sizeof(functionsLibCtx);
+    memory_overhead += curr_functions_lib_ctx->cache_memory;
+    memory_overhead += engine_cache_memory;
+
+    return memory_overhead;
+}
+
+/* Returns the number of functions */
+unsigned long functionsNum(void) {
+    return dictSize(curr_functions_lib_ctx->functions);
+}
+
+unsigned long functionsLibNum(void) {
+    return dictSize(curr_functions_lib_ctx->libraries);
+}
+
+dict* functionsLibGet(void) {
+    return curr_functions_lib_ctx->libraries;
+}
+
+size_t functionsLibCtxfunctionsLen(functionsLibCtx *functions_ctx) {
+    return dictSize(functions_ctx->functions);
+}
+
+/* Initialize engine data structures.
+ * Should be called once on server initialization */
+int functionsInit(void) {
+    engines = dictCreate(&engineDictType);
+
+    if (luaEngineInitEngine() != C_OK) {
+        return C_ERR;
+    }
+
+    /* Must be initialized after engines initialization */
+    curr_functions_lib_ctx = functionsLibCtxCreate();
+
+    return C_OK;
+}