Fixed some typos, add a spell check ci and others minor fix (#8890)

This PR adds a spell checker CI action that will fail future PRs if they introduce typos and spelling mistakes.
This spell checker is based on blacklist of common spelling mistakes, so it will not catch everything,
but at least it is also unlikely to cause false positives.

Besides that, the PR also fixes many spelling mistakes and types, not all are a result of the spell checker we use.

Here's a summary of other changes:
1. Scanned the entire source code and fixes all sorts of typos and spelling mistakes (including missing or extra spaces).
2. Outdated function / variable / argument names in comments
3. Fix outdated keyspace masks error log when we check `config.notify-keyspace-events` in loadServerConfigFromString.
4. Trim the white space at the end of line in `module.c`. Check: redis/redis#7751
5. Some outdated https link URLs.
6. Fix some outdated comment. Such as:
    - In README: about the rdb, we used to said create a `thread`, change to `process`
    - dbRandomKey function coment (about the dictGetRandomKey, change to dictGetFairRandomKey)
    - notifyKeyspaceEvent fucntion comment (add type arg)
    - Some others minor fix in comment (Most of them are incorrectly quoted by variable names)
7. Modified the error log so that users can easily distinguish between TCP and TLS in `changeBindAddr`

.github/.codespellrc

@@ -0,0 +1,5 @@
+[codespell]
+quiet-level = 2
+count =
+skip = ./deps,./src/crc16_slottable.h
+ignore-words = ./.github/wordlist.txt

.github/ISSUE_TEMPLATE/crash_report.md

@@ -14,7 +14,7 @@ Paste the complete crash log between the quotes below. Please include a few line
 ```
 ```
 
-**Aditional information**
+**Additional information**
 
 1. OS distribution and version
 2. Steps to reproduce (if any)

.github/wordlist.txt

@@ -0,0 +1,15 @@
+ake
+bale
+fle
+fo
+gameboy
+mutli
+nd
+nees
+oll
+optin
+ot
+smove
+te
+tre
+cancelability

.github/workflows/spell-check.yml

@@ -0,0 +1,25 @@
+# A CI action that using codespell to check spell.
+# .github/.codespellrc is a config file.
+# .github/wordlist.txt is a list of words that will ignore word checks.
+# More details please check the following link:
+# https://github.com/codespell-project/codespell
+name: Spellcheck
+
+on:
+  push:
+  pull_request:
+
+jobs:
+  build:
+    name: Spellcheck
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v2
+
+      - name: Install prerequisites
+        run: sudo pip install codespell==2.0.0
+
+      - name: Spell check
+        run: codespell --config=./.github/.codespellrc

CONTRIBUTING

@@ -18,7 +18,7 @@ all the support in the mailing list.
 
 There is also an active community of Redis users at Stack Overflow:
 
-    http://stackoverflow.com/questions/tagged/redis
+    https://stackoverflow.com/questions/tagged/redis
 
 Issues and pull requests for documentation belong on the redis-doc repo:
 
@@ -38,10 +38,10 @@ Here you'll see if there is consensus about your idea.
 2. If in step 1 you get an acknowledgment from the project leaders, use the
    following procedure to submit a patch:
 
-    a. Fork Redis on github ( http://help.github.com/fork-a-repo/ )
+    a. Fork Redis on github ( https://docs.github.com/en/github/getting-started-with-github/fork-a-repo )
     b. Create a topic branch (git checkout -b my_branch)
     c. Push to your branch (git push origin my_branch)
-    d. Initiate a pull request on github ( https://help.github.com/articles/creating-a-pull-request/ )
+    d. Initiate a pull request on github ( https://docs.github.com/en/github/collaborating-with-issues-and-pull-requests/creating-a-pull-request )
     e. Done :)
 
 3. Keep in mind that we are very overloaded, so issues and PRs sometimes wait

README.md

@@ -380,8 +380,8 @@ aof.c and rdb.c
 
 As you can guess from the names, these files implement the RDB and AOF
 persistence for Redis. Redis uses a persistence model based on the `fork()`
-system call in order to create a thread with the same (shared) memory
-content of the main Redis thread. This secondary thread dumps the content
+system call in order to create a process with the same (shared) memory
+content of the main Redis process. This secondary process dumps the content
 of the memory on disk. This is used by `rdb.c` to create the snapshots
 on disk and by `aof.c` in order to perform the AOF rewrite when the
 append only file gets too big.

sentinel.conf

@@ -178,7 +178,7 @@ acllog-max-len 128
 # incoming connections (via ACL), and for outgoing connections (via
 # sentinel-user and sentinel-pass) 
 #
-# The requirepass is not compatable with aclfile option and the ACL LOAD
+# The requirepass is not compatible with aclfile option and the ACL LOAD
 # command, these will cause requirepass to be ignored.
 
 # sentinel sentinel-user <username>

src/acl.c

@@ -1363,7 +1363,7 @@ int ACLCheckPubsubPerm(client *c, int idx, int count, int literal, int *idxptr)
 
 }
 
-/* Check whether the command is ready to be exceuted by ACLCheckCommandPerm.
+/* Check whether the command is ready to be executed by ACLCheckCommandPerm.
  * If check passes, then check whether pub/sub channels of the command is
  * ready to be executed by ACLCheckPubsubPerm */
 int ACLCheckAllPerm(client *c, int *idxptr) {
@@ -2254,8 +2254,8 @@ void authCommand(client *c) {
      * will just use "default" as username. */
     robj *username, *password;
     if (c->argc == 2) {
-        /* Mimic the old behavior of giving an error for the two commands
-         * from if no password is configured. */
+        /* Mimic the old behavior of giving an error for the two argument
+         * form if no password is configured. */
         if (DefaultUser->flags & USER_FLAG_NOPASS) {
             addReplyError(c,"AUTH <password> called without any password "
                             "configured for the default user. Are you sure "

src/aof.c

@@ -419,7 +419,7 @@ void flushAppendOnlyFile(int force) {
                  * than two seconds this is still ok. Postpone again. */
                 return;
             }
-            /* Otherwise fall trough, and go write since we can't wait
+            /* Otherwise fall through, and go write since we can't wait
              * over two seconds. */
             server.aof_delayed_fsync++;
             serverLog(LL_NOTICE,"Asynchronous AOF fsync is taking too long (disk is busy?). Writing the AOF buffer without waiting for fsync to complete, this may slow down Redis.");
@@ -1745,7 +1745,7 @@ int rewriteAppendOnlyFileBackground(void) {
         server.aof_rewrite_scheduled = 0;
         server.aof_rewrite_time_start = time(NULL);
 
-        /* We set appendseldb to -1 in order to force the next call to the
+        /* We set aof_selected_db to -1 in order to force the next call to the
          * feedAppendOnlyFile() to issue a SELECT command, so the differences
          * accumulated by the parent into server.aof_rewrite_buf will start
          * with a SELECT statement and it will be safe to merge. */
@@ -1885,7 +1885,7 @@ void backgroundRewriteDoneHandler(int exitcode, int bysignal) {
             oldfd = open(server.aof_filename,O_RDONLY|O_NONBLOCK);
         } else {
             /* AOF enabled */
-            oldfd = -1; /* We'll set this to the current AOF filedes later. */
+            oldfd = -1; /* We'll set this to the current AOF file descriptor later. */
         }
 
         /* Rename the temporary file. This will not unlink the target file if

src/bitops.c

@@ -472,7 +472,7 @@ int getBitfieldTypeFromArgument(client *c, robj *o, int *sign, int *bits) {
     return C_OK;
 }
 
-/* This is an helper function for commands implementations that need to write
+/* This is a helper function for commands implementations that need to write
  * bits to a string object. The command creates or pad with zeroes the string
  * so that the 'maxbit' bit can be addressed. The object is finally
  * returned. Otherwise if the key holds a wrong type NULL is returned and
@@ -1025,7 +1025,7 @@ void bitfieldGeneric(client *c, int flags) {
             return;
         }
 
-        /* Lookup by making room up to the farest bit reached by
+        /* Lookup by making room up to the farthest bit reached by
          * this operation. */
         if ((o = lookupStringForBitCommand(c,
             highest_write_offset)) == NULL) {

src/cli_common.c

@@ -166,7 +166,7 @@ ssize_t cliWriteConn(redisContext *c, const char *buf, size_t buf_len)
      *
      * Do we still have data that was there prior to our buf? If so,
      * restore buffer to it's original state and report no new data was
-     * writen.
+     * written.
      */
     if (sdslen(c->obuf) > buf_len) {
         sdsrange(c->obuf, 0, -(buf_len+1));

src/cli_common.h

@@ -16,9 +16,9 @@ typedef struct cliSSLconfig {
     char *cert;
     /* Private key file to authenticate with, or NULL */
     char *key;
-    /* Prefered cipher list, or NULL (applies only to <= TLSv1.2) */
+    /* Preferred cipher list, or NULL (applies only to <= TLSv1.2) */
     char* ciphers;
-    /* Prefered ciphersuites list, or NULL (applies only to TLSv1.3) */
+    /* Preferred ciphersuites list, or NULL (applies only to TLSv1.3) */
     char* ciphersuites;
 } cliSSLconfig;
 

src/cluster.c

@@ -1185,7 +1185,7 @@ void clusterHandleConfigEpochCollision(clusterNode *sender) {
  * CLUSTER nodes blacklist
  *
  * The nodes blacklist is just a way to ensure that a given node with a given
- * Node ID is not readded before some time elapsed (this time is specified
+ * Node ID is not re-added before some time elapsed (this time is specified
  * in seconds in CLUSTER_BLACKLIST_TTL).
  *
  * This is useful when we want to remove a node from the cluster completely:
@@ -4203,7 +4203,7 @@ sds clusterGenNodeDescription(clusterNode *node, int use_pport) {
                     "connected" : "disconnected");
 
     /* Slots served by this instance. If we already have slots info,
-     * append it diretly, otherwise, generate slots only if it has. */
+     * append it directly, otherwise, generate slots only if it has. */
     if (node->slots_info) {
         ci = sdscatsds(ci, node->slots_info);
     } else if (node->numslots > 0) {

src/config.c

@@ -581,7 +581,7 @@ void loadServerConfigFromString(char *config) {
             int flags = keyspaceEventsStringToFlags(argv[1]);
 
             if (flags == -1) {
-                err = "Invalid event class character. Use 'g$lshzxeA'.";
+                err = "Invalid event class character. Use 'Ag$lshzxeKEtmd'.";
                 goto loaderr;
             }
             server.notify_keyspace_events = flags;

src/connhelpers.h

@@ -41,7 +41,7 @@
  * of connections from within a handler.
  */
 
-/* Incremenet connection references.
+/* Increment connection references.
  *
  * Inside a connection handler, we guarantee refs >= 1 so it is always
  * safe to connClose().

src/crcspeed.c

@@ -248,7 +248,7 @@ uint16_t crcspeed16big(uint16_t big_table[8][256], uint16_t crc_in, void *buf,
 
 /* Return the CRC of buf[0..len-1] with initial crc, processing eight bytes
    at a time using passed-in lookup table.
-   This selects one of two routines depending on the endianess of
+   This selects one of two routines depending on the endianness of
    the architecture. */
 uint64_t crcspeed64native(uint64_t table[8][256], uint64_t crc, void *buf,
                           size_t len) {

src/db.c

@@ -295,7 +295,7 @@ robj *dbRandomKey(redisDb *db) {
                  * it could happen that all the keys are already logically
                  * expired in the slave, so the function cannot stop because
                  * expireIfNeeded() is false, nor it can stop because
-                 * dictGetRandomKey() returns NULL (there are keys to return).
+                 * dictGetFairRandomKey() returns NULL (there are keys to return).
                  * To prevent the infinite loop we do some tries, but if there
                  * are the conditions for an infinite loop, eventually we
                  * return a key name that may be already expired. */

src/debug.c

@@ -1980,7 +1980,7 @@ void disableWatchdog(void) {
  * of microseconds, i.e. -10 means 100 nanoseconds. */
 void debugDelay(int usec) {
     /* Since even the shortest sleep results in context switch and system call,
-     * the way we achive short sleeps is by statistically sleeping less often. */
+     * the way we achieve short sleeps is by statistically sleeping less often. */
     if (usec < 0) usec = (rand() % -usec) == 0 ? 1: 0;
     if (usec) usleep(usec);
 }

src/evict.c

@@ -133,7 +133,7 @@ void evictionPoolAlloc(void) {
     EvictionPoolLRU = ep;
 }
 
-/* This is an helper function for performEvictions(), it is used in order
+/* This is a helper function for performEvictions(), it is used in order
  * to populate the evictionPool with a few entries every time we want to
  * expire a key. Keys with idle time bigger than one of the current
  * keys are added. Keys are always added if there are free entries.

src/geo.c

@@ -213,7 +213,7 @@ void addReplyDoubleDistance(client *c, double d) {
  * representing a point, and a GeoShape, appends this entry as a geoPoint
  * into the specified geoArray only if the point is within the search area.
  *
- * returns C_OK if the point is included, or REIDS_ERR if it is outside. */
+ * returns C_OK if the point is included, or C_ERR if it is outside. */
 int geoAppendIfWithinShape(geoArray *ga, GeoShape *shape, double score, sds member) {
     double distance = 0, xy[2];
 
@@ -241,10 +241,10 @@ int geoAppendIfWithinShape(geoArray *ga, GeoShape *shape, double score, sds memb
 }
 
 /* Query a Redis sorted set to extract all the elements between 'min' and
- * 'max', appending them into the array of geoPoint structures 'gparray'.
+ * 'max', appending them into the array of geoPoint structures 'geoArray'.
  * The command returns the number of elements added to the array.
  *
- * Elements which are farest than 'radius' from the specified 'x' and 'y'
+ * Elements which are farther than 'radius' from the specified 'x' and 'y'
  * coordinates are not included.
  *
  * The ability of this function to append to an existing set of points is
@@ -330,7 +330,7 @@ void scoresOfGeoHashBox(GeoHashBits hash, GeoHashFix52Bits *min, GeoHashFix52Bit
      *
      * To get the min score we just use the initial hash value left
      * shifted enough to get the 52 bit value. Later we increment the
-     * 6 bit prefis (see the hash.bits++ statement), and get the new
+     * 6 bit prefix (see the hash.bits++ statement), and get the new
      * prefix: 101011, which we align again to 52 bits to get the maximum
      * value (which is excluded from the search). So we get everything
      * between the two following scores (represented in binary):

src/geohash_helper.c

@@ -216,7 +216,7 @@ GeoHashFix52Bits geohashAlign52Bits(const GeoHashBits hash) {
     return bits;
 }
 
-/* Calculate distance using haversin great circle distance formula. */
+/* Calculate distance using haversine great circle distance formula. */
 double geohashGetDistance(double lon1d, double lat1d, double lon2d, double lat2d) {
     double lat1r, lon1r, lat2r, lon2r, u, v;
     lat1r = deg_rad(lat1d);

src/hyperloglog.c

@@ -899,7 +899,7 @@ int hllSparseSet(robj *o, long index, uint8_t count) {
  * the element belongs to is incremented if needed.
  *
  * This function is actually a wrapper for hllSparseSet(), it only performs
- * the hashshing of the element to obtain the index and zeros run length. */
+ * the hashing of the element to obtain the index and zeros run length. */
 int hllSparseAdd(robj *o, unsigned char *ele, size_t elesize) {
     long index;
     uint8_t count = hllPatLen(ele,elesize,&index);

src/intset.c

@@ -306,7 +306,7 @@ int intsetValidateIntegrity(const unsigned char *p, size_t size, int deep) {
         return 0;
     }
 
-    /* check that the size matchies (all records are inside the buffer). */
+    /* check that the size matches (all records are inside the buffer). */
     uint32_t count = intrev32ifbe(is->length);
     if (sizeof(*is) + count*record_size != size)
         return 0;

src/listpack.c

@@ -116,7 +116,7 @@
     (p)[5] = ((v)>>8)&0xff; \
 } while(0)
 
-/* Validates that 'p' is not ouside the listpack.
+/* Validates that 'p' is not outside the listpack.
  * All function that return a pointer to an element in the listpack will assert
  * that this element is valid, so it can be freely used.
  * Generally functions such lpNext and lpDelete assume the input pointer is
@@ -125,7 +125,7 @@
     assert((p) >= (lp)+LP_HDR_SIZE && (p) < (lp)+lpGetTotalBytes((lp))); \
 } while (0)
 
-/* Similar to the above, but validates the entire element lenth rather than just
+/* Similar to the above, but validates the entire element length rather than just
  * it's pointer. */
 #define ASSERT_INTEGRITY_LEN(lp, p, len) do { \
     assert((p) >= (lp)+LP_HDR_SIZE && (p)+(len) < (lp)+lpGetTotalBytes((lp))); \
@@ -218,7 +218,7 @@ int lpStringToInt64(const char *s, unsigned long slen, int64_t *value) {
 /* Create a new, empty listpack.
  * On success the new listpack is returned, otherwise an error is returned.
  * Pre-allocate at least `capacity` bytes of memory,
- * over-allocated memory can be shrinked by `lpShrinkToFit`.
+ * over-allocated memory can be shrunk by `lpShrinkToFit`.
  * */
 unsigned char *lpNew(size_t capacity) {
     unsigned char *lp = lp_malloc(capacity > LP_HDR_SIZE+1 ? capacity : LP_HDR_SIZE+1);
@@ -416,7 +416,7 @@ uint32_t lpCurrentEncodedSizeUnsafe(unsigned char *p) {
 }
 
 /* Return bytes needed to encode the length of the listpack element pointed by 'p'.
- * This includes just the encodign byte, and the bytes needed to encode the length
+ * This includes just the encoding byte, and the bytes needed to encode the length
  * of the element (excluding the element data itself)
  * If the element encoding is wrong then 0 is returned. */
 uint32_t lpCurrentEncodedSizeBytes(unsigned char *p) {
@@ -641,7 +641,7 @@ unsigned char *lpGet(unsigned char *p, int64_t *count, unsigned char *intbuf) {
  *
  * If 'newp' is not NULL, at the end of a successful call '*newp' will be set
  * to the address of the element just added, so that it will be possible to
- * continue an interation with lpNext() and lpPrev().
+ * continue an interaction with lpNext() and lpPrev().
  *
  * For deletion operations ('ele' set to NULL) 'newp' is set to the next
  * element, on the right of the deleted one, or to NULL if the deleted element
@@ -879,7 +879,7 @@ int lpValidateNext(unsigned char *lp, unsigned char **pp, size_t lpbytes) {
     if (!lenbytes)
         return 0;
 
-    /* make sure the encoded entry length doesn't rech outside the edge of the listpack */
+    /* make sure the encoded entry length doesn't reach outside the edge of the listpack */
     if (OUT_OF_RANGE(p + lenbytes))
         return 0;
 
@@ -888,7 +888,7 @@ int lpValidateNext(unsigned char *lp, unsigned char **pp, size_t lpbytes) {
     unsigned long encodedBacklen = lpEncodeBacklen(NULL,entrylen);
     entrylen += encodedBacklen;
 
-    /* make sure the entry doesn't rech outside the edge of the listpack */
+    /* make sure the entry doesn't reach outside the edge of the listpack */
     if (OUT_OF_RANGE(p + entrylen))
         return 0;
 
@@ -925,7 +925,7 @@ int lpValidateIntegrity(unsigned char *lp, size_t size, int deep){
     if (!deep)
         return 1;
 
-    /* Validate the invividual entries. */
+    /* Validate the individual entries. */
     uint32_t count = 0;
     unsigned char *p = lpFirst(lp);
     while(p) {

src/lolwut.c

@@ -84,7 +84,7 @@ void lolwutCommand(client *c) {
     }
 }
 
-/* ========================== LOLWUT Canvase ===============================
+/* ========================== LOLWUT Canvas ===============================
  * Many LOLWUT versions will likely print some computer art to the screen.
  * This is the case with LOLWUT 5 and LOLWUT 6, so here there is a generic
  * canvas implementation that can be reused.  */