Replace bucket_id_strcrc32() with bucket_id_mpcrc32()

Function `bucket_id_mpcrc32()` is safer than `bucket_id_strcrc32()` [1].
It takes a CRC32 from a MessagePack encoded value. That is, bucket id of
integers does not depend on their Lua type. In case of a string key, it
does not encode it into MessagePack, but takes a hash right from the
string.

Actually we already had `bucket_id_mpcrc32()` but in commit "Change
bucket_id function" (97835b9) hash
function has been changed to `bucket_id_strcrc32()`.

1. https://www.tarantool.io/en/doc/latest/reference/reference_rock/vshard/vshard_api/#lua-function.vshard.router.bucket_id_mpcrc32

Author: ligurio

README.md

@@ -49,7 +49,7 @@ crud.unflatten_rows(res.rows, res.metadata)
 **Notes:**
 
 * A space should have a format.
-* By default, `bucket_id` is computed as `vshard.router.bucket_id_strcrc32(key)`,
+* By default, `bucket_id` is computed as `vshard.router.bucket_id_mpcrc32(key)`,
   where `key` is the primary key value.
   Custom bucket ID can be specified as `opts.bucket_id` for each operation.
   For operations that accepts tuple/object bucket ID can be specified as

crud/common/sharding.lua

@@ -12,7 +12,7 @@ function sharding.key_get_bucket_id(key, specified_bucket_id)
         return specified_bucket_id
     end
 
-    return vshard.router.bucket_id_strcrc32(key)
+    return vshard.router.bucket_id_mpcrc32(key)
 end
 
 function sharding.tuple_get_bucket_id(tuple, space, specified_bucket_id)

crud/delete.lua

@@ -94,7 +94,7 @@ end
 --
 -- @tparam ?number opts.bucket_id
 --  Bucket ID
---  (by default, it's vshard.router.bucket_id_strcrc32 of primary key)
+--  (by default, it's vshard.router.bucket_id_mpcrc32 of primary key)
 --
 -- @return[1] object
 -- @treturn[2] nil

crud/get.lua

@@ -104,7 +104,7 @@ end
 --
 -- @tparam ?number opts.bucket_id
 --  Bucket ID
---  (by default, it's vshard.router.bucket_id_strcrc32 of primary key)
+--  (by default, it's vshard.router.bucket_id_mpcrc32 of primary key)
 --
 -- @tparam ?boolean opts.prefer_replica
 --  Call on replica if it's possible

crud/insert.lua

@@ -107,7 +107,7 @@ end
 --
 -- @tparam ?number opts.bucket_id
 --  Bucket ID
---  (by default, it's vshard.router.bucket_id_strcrc32 of primary key)
+--  (by default, it's vshard.router.bucket_id_mpcrc32 of primary key)
 --
 -- @return[1] tuple
 -- @treturn[2] nil

crud/replace.lua

@@ -111,7 +111,7 @@ end
 --
 -- @tparam ?number opts.bucket_id
 --  Bucket ID
---  (by default, it's vshard.router.bucket_id_strcrc32 of primary key)
+--  (by default, it's vshard.router.bucket_id_mpcrc32 of primary key)
 --
 -- @return[1] object
 -- @treturn[2] nil

crud/update.lua

@@ -134,7 +134,7 @@ end
 --
 -- @tparam ?number opts.bucket_id
 --  Bucket ID
---  (by default, it's vshard.router.bucket_id_strcrc32 of primary key)
+--  (by default, it's vshard.router.bucket_id_mpcrc32 of primary key)
 --
 -- @return[1] object
 -- @treturn[2] nil

crud/upsert.lua

@@ -116,7 +116,7 @@ end
 --
 -- @tparam ?number opts.bucket_id
 --  Bucket ID
---  (by default, it's vshard.router.bucket_id_strcrc32 of primary key)
+--  (by default, it's vshard.router.bucket_id_mpcrc32 of primary key)
 --
 -- @return[1] tuple
 -- @treturn[2] nil