Update blockchain.cpp

src/gausskernel/security/gs_ledger/blockchain.cpp

@@ -30,6 +30,32 @@
 #include "libpq/md5.h"
 #include "gs_ledger/blockchain.h"
 #include "utils/snapmgr.h"
+/*Blockchain was first used in the Bitcoin project to provide a distributed accounting 
+platform for the operation of Bitcoin. With the development of blockchain technology,
+the definition of blockchain is that a blockchain is a distributed database, which maintains 
+a continuously growing data record chain and can prevent data from being tampered with. 
+It consists of data structure blocks, which hold proprietary data in the initial blockchain 
+implementation, and the data and programs are saved in some recent implementations, 
+and each block holds some personal transaction data and block execution results. Each 
+block contains a timestamp and information of the previous block. Blockchain is a 
+decentralized recording technology. In other words, any node participating in the system
+may not belong to the same organization and need not trust each other; Blockchain 
+data is maintained by all node functions, and each participating node can copy and 
+obtain a complete copy of the record.
+
+The basic concepts of blockchain are:
+Transaction: that is, an operation that changes the account book status once, such as adding a record.
+
+Block: It records the transactions and status results in a period of time, 
+which is a consensus on the current account book status.
+
+Chain: It is composed of blocks connected in series according to 
+the sequence of occurrence, and it is a log record of the whole state change.
+
+If the blockchain is regarded as a state machine, each transaction is an attempt to change the state, 
+and the block generated by each consensus is the result that 
+the parameter confirms the state change caused by all the transactions in the block.
+*/
 
 /*
  * gen_global_hash -- generate globalhash of gchain
@@ -41,6 +67,11 @@
  *
  * Note: globalhash is generated by operate info and previous globalhash using md5.
  */
+
+/*Function name: gen_ Global_ Hash
+Formal parameters: (hash32_t * hash_buffer, const char * info_string, bool exist, const hash32_t * prev_hash)
+Return value: bool
+Generate global hash for gchain*/
 bool gen_global_hash(hash32_t *hash_buffer, const char *info_string, bool exist, const hash32_t *prev_hash)
 {
     errno_t rc = EOK;
@@ -87,6 +118,11 @@ bool gen_global_hash(hash32_t *hash_buffer, const char *info_string, bool exist,
  * cmd_text: the command query which modified user table.
  * rel_hash: rel_hash of current block.
  */
+/*Function name: set_ Gchain_ Comb_ String
+Formal parameters (const char * dbname, const char * username,
+Const char * nsp_ Name, const char * rel_ Name, const char * cmd_ Text, uint64 rel_ Hash)
+Return value: char*
+Set combo block information*/
 char *set_gchain_comb_string(const char *db_name, const char *user_name,
     const char *nsp_name, const char *rel_name, const char *cmd_text, uint64 rel_hash)
 {
@@ -113,6 +149,10 @@ char *set_gchain_comb_string(const char *db_name, const char *user_name,
  * into gchain cache for next block. Thus, previous global hash is
  * come from cache directly.
  */
+/*Function name: ledger_ Gchain_ Append
+Formal parameters: (Oid relid, const char * query_string, uint64 cn_hash)
+Return value: void
+Record the block to gchain.*/
 void ledger_gchain_append(Oid relid, const char *query_string, uint64 cn_hash)
 {
     Datum current_time;
@@ -173,6 +213,10 @@ void ledger_gchain_append(Oid relid, const char *query_string, uint64 cn_hash)
  * operation: command operation.
  * hash: the hash that prepare to append.
  */
+/*Function name: ledger_ Output_ Append_ Hash
+Formal parameters: (char * resp_tag, CmdType operation, uint64 hash)
+Return value: void
+Append relhash to the response tag.*/
 static void ledger_output_append_hash(char *resp_tag, CmdType operation, uint64 hash)
 {
     Assert(resp_tag != NULL);
@@ -202,6 +246,10 @@ static void ledger_output_append_hash(char *resp_tag, CmdType operation, uint64
  * use es_modifiedRowHash to receive all DN relhash and accumulate them
  * as cn_relhash for insertion.
  */
+/*Function name: ledger_ ExecutorEnd
+Formal parameter: (QueryDesc * query_desc)
+Return value: void
+Record the end block to gchain.*/
 static void ledger_ExecutorEnd(QueryDesc *query_desc)
 {
     uint64 hashsum;
@@ -302,6 +350,10 @@ void opfusion_ledger_ExecutorEnd(FusionType fusiontype, Oid relid, const char *q
 /*
  * ledger_hook_init -- install of gchain block record hook.
  */
+/*Function name: ledger_ Hook_ Init
+Formal parameter: void
+Return value: void
+The gchain block records the installation of hooks.*/
 void ledger_hook_init(void)
 {
     t_thrd.security_ledger_cxt.prev_ExecutorEnd = (void *)ExecutorEnd_hook;
@@ -311,6 +363,10 @@ void ledger_hook_init(void)
 /*
  * ledger_hook_fini -- uninstall of gchain block record hook.
  */
+/*Function name: ledger_ Hook_ Init
+Formal parameter: void
+Return value: void
+The gchain block records the installation of hooks.*/
 void ledger_hook_fini(void)
 {
     ExecutorEnd_hook = (ExecutorEnd_hook_type)t_thrd.security_ledger_cxt.prev_ExecutorEnd;