From b7b8eb2ecb7ee6ba305771c5414050453e56a24c Mon Sep 17 00:00:00 2001
From: John Sully <john@csquare.ca>
Date: Tue, 21 Jan 2020 19:51:16 -0500
Subject: [PATCH] Missing cron files

Former-commit-id: c983d57f739cc9b4b8271a6d069fad1b5a9d3dad
---
 src/cron.cpp | 126 +++++++++++++++++++++++++++++++++++++++++++++++++++
 src/cron.h   |  16 +++++++
 2 files changed, 142 insertions(+)
 create mode 100644 src/cron.cpp
 create mode 100644 src/cron.h

diff --git a/src/cron.cpp b/src/cron.cpp
new file mode 100644
index 000000000..72d26f5c3
--- /dev/null
+++ b/src/cron.cpp
@@ -0,0 +1,126 @@
+#include "server.h"
+#include "cron.h"
+
+void freeCronObject(robj_roptr o)
+{
+    delete reinterpret_cast<const cronjob*>(ptrFromObj(o));
+}
+
+// CRON [name] [single shot] [optional: start] [delay] [script] [numkeys] [key N] [arg N]
+void cronCommand(client *c)
+{
+    int arg_offset = 0;
+    static const int ARG_NAME = 1;
+    static const int ARG_SINGLESHOT = 2;
+    static const int ARG_EXPIRE = 3;
+    #define ARG_SCRIPT (4+arg_offset)
+    #define ARG_NUMKEYS (5+arg_offset)
+    #define ARG_KEYSTART (6+arg_offset)
+
+    bool fSingleShot = false;
+    if (strcasecmp("single", szFromObj(c->argv[ARG_SINGLESHOT])) == 0) {
+        fSingleShot = true;
+    } else {
+        if (strcasecmp("repeat", szFromObj(c->argv[ARG_SINGLESHOT])) != 0) {
+            addReply(c, shared.syntaxerr);
+            return;
+        }
+    }
+
+    long long interval;
+    if (getLongLongFromObjectOrReply(c, c->argv[ARG_EXPIRE], &interval, "missing expire time") != C_OK)
+        return;
+
+    long long base = g_pserver->mstime;
+    if (getLongLongFromObject(c->argv[ARG_EXPIRE+1], &base) == C_OK) {
+        arg_offset++;
+        std::swap(base, interval);
+    }
+
+    if (interval <= 0)
+    {
+        addReplyError(c, "interval must be positive");
+        return;
+    }
+
+    long numkeys = 0;
+    if (c->argc > ARG_NUMKEYS)
+    {
+        if (getLongFromObjectOrReply(c, c->argv[ARG_NUMKEYS], &numkeys, NULL) != C_OK)
+            return;
+        
+        if (c->argc < (6 + numkeys)) {
+            addReplyError(c, "Missing arguments or numkeys is too big");
+        }
+    }
+
+    std::unique_ptr<cronjob> spjob = std::make_unique<cronjob>();
+    spjob->script = sdsstring(sdsdup(szFromObj(c->argv[ARG_SCRIPT])));
+    spjob->interval = (uint64_t)interval;
+    spjob->startTime = (uint64_t)base;
+    spjob->fSingleShot = fSingleShot;
+    spjob->dbNum = c->db - g_pserver->db;
+    for (long i = 0; i < numkeys; ++i)
+        spjob->veckeys.emplace_back(sdsdup(szFromObj(c->argv[ARG_KEYSTART+i])));
+    for (long i = ARG_KEYSTART + numkeys; i < c->argc; ++i)
+        spjob->vecargs.emplace_back(sdsdup(szFromObj(c->argv[i])));
+
+    robj *o = createObject(OBJ_CRON, spjob.release());
+    setKey(c->db, c->argv[ARG_NAME], o);
+    // use an expire to trigger execution.  Note: We use a subkey expire here so legacy clients don't delete it.
+    setExpire(c, c->db, c->argv[ARG_NAME], c->argv[ARG_NAME], base + interval);
+    addReply(c, shared.ok);
+}
+
+void executeCronJobExpireHook(const char *key, robj *o)
+{
+    serverAssert(o->type == OBJ_CRON);
+    cronjob *job = (cronjob*)ptrFromObj(o);
+    
+    client *cFake = createClient(-1, IDX_EVENT_LOOP_MAIN);
+    cFake->lock.lock();
+    cFake->authenticated = 1;
+    cFake->puser = nullptr;
+    selectDb(cFake, job->dbNum);
+    serverAssert(cFake->argc == 0);
+
+    // Setup the args for the EVAL command
+    cFake->argc = 3 + job->veckeys.size() + job->vecargs.size();
+    cFake->argv = (robj**)zmalloc(sizeof(robj*) * cFake->argc, MALLOC_LOCAL);
+    cFake->argv[0] = createStringObject("EVAL", 4);
+    cFake->argv[1] = createStringObject(job->script.get(), job->script.size());
+    cFake->argv[2] = createStringObjectFromLongLong(job->veckeys.size());
+    for (size_t i = 0; i < job->veckeys.size(); ++i)
+        cFake->argv[3+i] = createStringObject(job->veckeys[i].get(), job->veckeys[i].size());
+    for (size_t i = 0; i < job->vecargs.size(); ++i)
+        cFake->argv[3+job->veckeys.size()+i] = createStringObject(job->vecargs[i].get(), job->vecargs[i].size());
+
+    evalCommand(cFake);
+    resetClient(cFake);
+
+    robj *keyobj = createStringObject(key,sdslen(key));
+    int dbId = job->dbNum;
+    if (job->fSingleShot)
+    {
+        dbSyncDelete(cFake->db, keyobj);
+    }
+    else
+    {
+        job->startTime += job->interval;
+        if (job->startTime < (uint64_t)g_pserver->mstime)
+        {
+            // If we are more than one interval in the past then fast forward to
+            //  the first interval still in the future
+            auto delta = g_pserver->mstime - job->startTime;
+            auto multiple = (delta / job->interval)+1;
+            job->startTime += job->interval * multiple;
+        }
+        setExpire(cFake, cFake->db, keyobj, keyobj, job->startTime + job->interval);
+    }
+
+    notifyKeyspaceEvent(NOTIFY_KEYEVENT, "CRON Executed", keyobj, dbId);
+    decrRefCount(keyobj);
+
+    // o is invalid at this point
+    freeClient(cFake);
+}
\ No newline at end of file
diff --git a/src/cron.h b/src/cron.h
new file mode 100644
index 000000000..8bac7f604
--- /dev/null
+++ b/src/cron.h
@@ -0,0 +1,16 @@
+#pragma once
+
+struct cronjob
+{
+    sdsstring script;
+    uint64_t interval;
+    uint64_t startTime;
+    std::vector<sdsstring> veckeys;
+    std::vector<sdsstring> vecargs;
+    int dbNum = 0;
+    bool fSingleShot = false;
+};
+
+void freeCronObject(robj_roptr o);
+void executeCronJobExpireHook(const char *key, robj *o);
+void cronCommand(client *c);
\ No newline at end of file