gvsafronov/fbx
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

add top clause

Browse Source
This commit is contained in:
Kenneth Cheng 2020-05-02 16:28:53 +08:00
parent fd709d62f7
commit 730886651a
2 changed files with 79 additions and 41 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
README.md
View File

@ -3,7 +3,7 @@
This module aims to provide simple DML to manipulate the hashes in REDIS for SQL users. It works as simple as you expected. It translates the input statement to a set of pure REDIS commands. It does not need nor generate any intermediate stuffs which occupied your storages. The target data is your hashes only.
## Usage
```bash
```sql
$ redis-cli
127.0.0.1:6379> hmset phonebook:0001 name "Peter Nelson" tel "1-456-1246-3421" birth "2019-10-01" pos 3 gender "M"
127.0.0.1:6379> hmset phonebook:0002 name "Betty Joan" tel "1-444-9999-1112" birth "2019-12-01" pos 1 gender "F"
@ -23,7 +23,7 @@ $ redis-cli
## Getting started
### Get the package and build the binary:
```bash
```sql
$ git clone https://github.com/cscan/dbx.git
$ cd dbx/src && make
```
@ -33,17 +33,17 @@ This plugin library is written in pure C. A file dbx.so is built after successfu
### Load the module in redis (3 ways)
1. Load the module in CLI
```bash
```sql
127.0.0.1:6379> module load /path/to/dbx.so
```
2. Start the server with loadmodule argument
```bash
```sql
$ redis-server --loadmodule /path/to/dbx.so
```
3. Adding the following line in the file redis.conf and then restart the server
```bash
```sql
loadmodule /path/to/dbx.so
```
@ -53,7 +53,7 @@ If you still have problem in loading the module, please visit: https://redis.io/
#### Select Statement
You may specify multiple fields separated by comma
```bash
```sql
127.0.0.1:6379> dbx select name, gender, birth from phonebook
1) 1) name
2) "Betty Joan"
@ -82,7 +82,7 @@ You may specify multiple fields separated by comma
```
"*" is support
```bash
```sql
127.0.0.1:6379> dbx select * from phonebook where birth > '2019-11-11'
1) 1) "name"
2) "Betty Joan"
@ -97,7 +97,7 @@ You may specify multiple fields separated by comma
```
If you want to show the exact keys, you may try rowid()
```bash
```sql
127.0.0.1:6379> dbx select rowid() from phonebook
1) 1) rowid()
2) "phonebook:1588299191-764848276"
@ -110,7 +110,7 @@ If you want to show the exact keys, you may try rowid()
```
The above is nearly like REDIS keys command
```bash
```sql
127.0.0.1:6379> keys phonebook*
1) "phonebook:1588298418-551514504"
2) "phonebook:1588299196-2115347437"
@ -122,7 +122,7 @@ Each record is exactly a hash, you could use raw REDIS commands ``hget, hmget or
#### Where Clause in Select Statement
Your could specify =, >, <, >=, <=, <>, != or like conditions in where clause. Now the module only support "and" to join multiple conditions.
```bash
```sql
127.0.0.1:6379> dbx select tel from phonebook where name like Son
1) 1) tel
2) "1-888-3333-1412"
@ -135,7 +135,7 @@ Your could specify =, >, <, >=, <=, <>, != or like conditions in where clause. N
#### Order Clause in Select Statement
Ordering can be ascending or descending. All sortings are alpha-sort.
```bash
```sql
127.0.0.1:6379> dbx select * from phonebook order by pos asc
...
127.0.0.1:6379> dbx select * from phonebook order by pos desc
@ -144,12 +144,17 @@ Ordering can be ascending or descending. All sortings are alpha-sort.
#### Into Clause in Select Statement
You could create another table by into clause.
```bash
```sql
127.0.0.1:6379> dbx select * into testbook from phonebook
1) testbook:1588325407-1751904058
2) testbook:1588325407-1751904059
3) testbook:1588325407-1751904060
4) testbook:1588325407-1751904061
127.0.0.1:6379> keys testbook*
1) "testbook:1588325407-1751904061"
2) "testbook:1588325407-1751904059"
3) "testbook:1588325407-1751904058"
4) "testbook:1588325407-1751904060"
127.0.0.1:6379> dbx select * from testbook
1) 1) "name"
2) "Mattias Swensson"
@ -195,7 +200,7 @@ You could create another table by into clause.
#### Delete Statement
You may also use Insert and Delete statement to operate the hash. If you does not provide the where clause, it will delete all the records of the specified key prefix. (i.e. phonebook)
```bash
```sql
127.0.0.1:6379> dbx delete from phonebook where gender = F
(integer) 2
127.0.0.1:6379> dbx delete from phonebook
@ -204,7 +209,7 @@ You may also use Insert and Delete statement to operate the hash. If you does no
#### Insert Statement
The module provide simple Insert statement which same as the function of the REDIS command hmset. It will append a random string to your provided key (i.e. phonebook). If operation is successful, it will return the key name.
```bash
```sql
127.0.0.1:6379> dbx insert into phonebook (name,tel,birth,pos,gender) values ('Peter Nelson' ,1-456-1246-3421, 2019-10-01, 3, M)
"phonebook:1588298418-551514504"
127.0.0.1:6379> dbx insert into phonebook (name,tel,birth,pos,gender) values ('Betty Joan' ,1-444-9999-1112, 2019-12-01, 1, F)
@ -213,15 +218,27 @@ The module provide simple Insert statement which same as the function of the RED
"phonebook:1588299196-2115347437"
127.0.0.1:6379> dbx insert into phonebook (name,tel,birth,pos,gender) values ('Mattias Swensson' ,1-888-3333-1412, 2017-06-30, 4, M)
"phonebook:1588299202-1052597574"
127.0.0.1:6379> hgetall phonebook:1588298418-551514504
1) "name"
2) "Peter Nelson"
3) "tel"
4) "1-456-1246-3421"
5) "birth"
6) "2019-10-01"
7) "pos"
8) "3"
9) "gender"
10) "M"
127.0.0.1:6379>
```
Note that Redis requires at least one space after the single and double quoted arguments.
Or you may quote the whole SQL statement as below:
```bash
```sql
127.0.0.1:6379> dbx "insert into phonebook (name,tel,birth,pos,gender) values ('Peter Nelson','1-456-1246-3421','2019-10-01',3, 'M')"
```
#### Issue command from BASH shell
```bash
```sql
$ redis-cli dbx select "*" from phonebook where gender = M order by pos desc
1) 1) "name"
2) "Mattias Swensson"
@ -248,7 +265,7 @@ $ redis-cli dbx select name from phonebook where tel like 9812
2) "Bloody Mary"
```
Note that "*" requires double quoted otherwise it will pass all the filename in current directory. Of course you could quote the whole SQL statement.
```bash
```sql
$ redis-cli dbx "select * from phonebook where gender = M order by pos desc"
```

69
src/dbx.c
View File

@ -220,7 +220,7 @@ Vector* splitWhereString(char *s) {
return v;
}
int processRecords(RedisModuleCtx *ctx, RedisModuleCallReply *keys, regex_t *r, Vector *vSelect, Vector *vWhere, char *intoKey) {
size_t processRecords(RedisModuleCtx *ctx, RedisModuleCallReply *keys, regex_t *r, Vector *vSelect, Vector *vWhere, char *intoKey, long top) {
size_t nKeys = RedisModule_CallReplyLength(keys);
size_t affected = 0;
for (size_t i = 0; i < nKeys; i++) {
@ -234,6 +234,8 @@ int processRecords(RedisModuleCtx *ctx, RedisModuleCallReply *keys, regex_t *r,
else
showRecord(ctx, key, vSelect);
affected++;
top--;
printf("%zu\n", affected);
}
}
RedisModule_FreeString(ctx, key);
@ -242,7 +244,7 @@ int processRecords(RedisModuleCtx *ctx, RedisModuleCallReply *keys, regex_t *r,
}
/* Create temporary set for sorting */
int buildSetByPattern(RedisModuleCtx *ctx, regex_t *r, char *setName, Vector *vWhere) {
size_t buildSetByPattern(RedisModuleCtx *ctx, regex_t *r, char *setName, Vector *vWhere) {
RedisModule_Call(ctx, "DEL", "c", setName);
RedisModuleString *scursor = RedisModule_CreateStringFromLongLong(ctx, 0);
long long lcursor;
@ -282,6 +284,7 @@ int SelectCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
return RedisModule_WrongArity(ctx);
// Table
long top = 0;
RedisModuleString *fromKeys;
char intoKey[32] = "";
@ -327,10 +330,28 @@ int SelectCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
}
switch(step) {
case 0:
if (strcmp("top", token) == 0) {
step = -2;
break;
}
step = -1;
case -1:
if (strlen(token) > 512) {
RedisModule_ReplyWithError(ctx, "select arguments are too long");
return REDISMODULE_ERR;
}
strcat(stmSelect, token);
step = -3;
break;
case -2:
top = atol(token);
step = -1;
break;
case -3:
if (strcmp("into", token) == 0)
step = -1;
step = -4;
else if (strcmp("from", token) == 0)
step = -3;
step = -6;
else {
if (strlen(stmSelect) + strlen(token) > 512) {
RedisModule_ReplyWithError(ctx, "select arguments are too long");
@ -339,35 +360,35 @@ int SelectCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
strcat(stmSelect, token);
}
break;
case -1:
case -4:
// parse into clause, assume time+rand always is new key
strcpy(intoKey, token);
step = -2;
step = -5;
break;
case -2:
case -5:
if (strcmp("from", token) == 0)
step = -3;
step = -6;
else {
RedisModule_ReplyWithError(ctx, "from keyword is expected");
return REDISMODULE_ERR;
}
break;
case -3:
case -6:
// parse from clause
fromKeys = RMUtil_CreateFormattedString(ctx, token);
step = 4;
step = 7;
break;
case 4:
case 7:
if (strcmp("where", token) == 0)
step = -5;
step = -8;
else if (strcmp("order", token) == 0)
step = -7;
step = -10;
break;
case -5:
case 6:
case -8:
case 9:
// parse where clause
if (strcmp("order", token) == 0)
step = -7;
step = -10;
else if (strcmp("and", token) == 0)
strcat(stmWhere, "&&");
else {
@ -378,19 +399,19 @@ int SelectCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
char *p = token;
while (*p++) *p = *p == 7? 32: *p;
strcat(stmWhere, token);
step = 6;
step = 9;
}
break;
case -7:
case -10:
if (strcmp("by", token) == 0)
step = -8;
step = -11;
else {
RedisModule_ReplyWithError(ctx, "missing 'by' after order");
return REDISMODULE_ERR;
}
break;
case -8:
case 9:
case -11:
case 12:
// parse order clause
if (strlen(stmOrder) + strlen(token) > 512) {
RedisModule_ReplyWithError(ctx, "order arguments are too long");
@ -401,7 +422,7 @@ int SelectCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
else
if (strcmp("asc", token) != 0)
strcat(stmOrder, token);
step = 9;
step = 12;
break;
}
token = strtok(NULL, " ");
@ -447,7 +468,7 @@ int SelectCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
sprintf(stmt, "*->%s", field);
rep = RedisModule_Call(ctx, "SORT", "cccc", setName, "by", stmt, "alpha");
}
size_t n = processRecords(ctx, rep, &regex, vSelect, NULL, intoKey);
size_t n = processRecords(ctx, rep, &regex, vSelect, NULL, intoKey, top);
RedisModule_FreeCallReply(rep);
// set number of output
@ -473,7 +494,7 @@ int SelectCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
/* Filter by pattern matching. */
RedisModuleCallReply *rkeys = RedisModule_CallReplyArrayElement(rep, 1);
n += processRecords(ctx, rkeys, &regex, vSelect, vWhere, intoKey);
n += processRecords(ctx, rkeys, &regex, vSelect, vWhere, intoKey, top);
RedisModule_FreeCallReply(rep);
} while (lcursor);