feat: databend-meta transaction support generic bool-expression

Since this commit, application is allowed to specify a complex bool
expressions as the transaction predicate.

For example, the following transaction will be processed if:
`(a == 1 || b == 2) && (x == 3 or y == 4)`

```rust
let eq = |key: &str, val: &str| TxnCondition::eq_value(sample(key), b(val));

TxnRequest{
    condition: vec![],
    condition_tree: Some(
            eq("a", 1).or(eq("b", 2))
            .and(
                eq("x", 3).or(eq("y", 4))
            ))
    // ...
}
```

For backward compatibility, both already existing `condition` and the new
`condition_tree` will be evaluated: transaction will be processed only
when both of them evaluated to be `true`.

src/meta/api/src/schema_api_impl.rs

@@ -445,6 +445,7 @@ impl<KV: kvapi::KVApi<Error = MetaError> + ?Sized> SchemaApi for KV {
                         txn_cond_seq(&dbid_idlist, Eq, db_id_list_seq),
                         txn_cond_seq(&dbid, Eq, db_meta_seq),
                     ],
+                    condition_tree: None,
                     if_then: vec![
                         txn_op_put(name_key, serialize_u64(db_id)?), // (tenant, db_name) -> db_id
                         txn_op_put(&dbid, serialize_struct(&db_meta)?), // (db_id) -> db_meta
@@ -596,6 +597,7 @@ impl<KV: kvapi::KVApi<Error = MetaError> + ?Sized> SchemaApi for KV {
 
             let txn_req = TxnRequest {
                 condition,
+                condition_tree: None,
                 if_then,
                 else_then: vec![],
             };
@@ -1416,6 +1418,7 @@ impl<KV: kvapi::KVApi<Error = MetaError> + ?Sized> SchemaApi for KV {
                         txn_cond_seq(&new_dbid_tbname_idlist, Eq, new_tb_id_list_seq),
                         txn_cond_seq(&table_id_to_name_key, Eq, table_id_to_name_seq),
                     ],
+                    condition_tree: None,
                     if_then: vec![
                         txn_op_del(&dbid_tbname), // (db_id, tb_name) -> tb_id
                         txn_op_put(&newdbid_newtbname, serialize_u64(table_id)?), /* (db_id, new_tb_name) -> tb_id */
@@ -1921,6 +1924,7 @@ impl<KV: kvapi::KVApi<Error = MetaError> + ?Sized> SchemaApi for KV {
                         txn_cond_seq(&orphan_dbid_tbname_idlist, Eq, orphan_tb_id_list.seq),
                         txn_cond_seq(&dbid_tbname_idlist, Eq, tb_id_list.seq),
                     ],
+                    condition_tree: None,
                     if_then: vec![
                         // Changing a table in a db has to update the seq of db_meta,
                         // to block the batch-delete-tables when deleting a db.
@@ -2063,6 +2067,7 @@ impl<KV: kvapi::KVApi<Error = MetaError> + ?Sized> SchemaApi for KV {
         for chunk in copied_files.chunks(chunk_size as usize) {
             let txn = TxnRequest {
                 condition: vec![],
+                condition_tree: None,
                 if_then: chunk
                     .iter()
                     .map(|(name, seq_file)| {
@@ -2382,6 +2387,7 @@ impl<KV: kvapi::KVApi<Error = MetaError> + ?Sized> SchemaApi for KV {
                     // table is not changed
                     txn_cond_seq(&tbid, Eq, seq_meta.seq),
                 ],
+                condition_tree: None,
                 if_then: vec![
                     txn_op_put(&tbid, serialize_struct(&new_table_meta)?), // tb_id -> tb_meta
                 ],
@@ -2487,6 +2493,7 @@ impl<KV: kvapi::KVApi<Error = MetaError> + ?Sized> SchemaApi for KV {
 
             let txn_req = TxnRequest {
                 condition: vec![txn_cond_eq_seq(&tbid, tb_meta_seq)],
+                condition_tree: None,
                 if_then: vec![
                     txn_op_put_pb(&tbid, &table_meta, None)?, // tb_id -> tb_meta
                 ],
@@ -2545,6 +2552,7 @@ impl<KV: kvapi::KVApi<Error = MetaError> + ?Sized> SchemaApi for KV {
                     // table is not changed
                     txn_cond_seq(&tbid, Eq, seq_meta.seq),
                 ],
+                condition_tree: None,
                 if_then: vec![
                     txn_op_put(&tbid, serialize_struct(&table_meta)?), // tb_id -> tb_meta
                 ],
@@ -2744,6 +2752,7 @@ impl<KV: kvapi::KVApi<Error = MetaError> + ?Sized> SchemaApi for KV {
             ];
             let txn_req = TxnRequest {
                 condition,
+                condition_tree: None,
                 if_then,
                 else_then: vec![],
             };
@@ -3055,6 +3064,7 @@ impl<KV: kvapi::KVApi<Error = MetaError> + ?Sized> SchemaApi for KV {
 
             let txn_req = TxnRequest {
                 condition,
+                condition_tree: None,
                 if_then,
                 else_then: vec![],
             };
@@ -4052,6 +4062,7 @@ async fn handle_undrop_table(
                     // table is not changed
                     txn_cond_eq_seq(&tbid, seq_table_meta.seq),
                 ],
+                condition_tree: None,
                 if_then: vec![
                     // Changing a table in a db has to update the seq of db_meta,
                     // to block the batch-delete-tables when deleting a db.

src/meta/api/src/sequence_api_impl.rs

@@ -144,6 +144,7 @@ impl<KV: kvapi::KVApi<Error = MetaError> + ?Sized> SequenceApi for KV {
 
             let txn_req = TxnRequest {
                 condition,
+                condition_tree: None,
                 if_then,
                 else_then: vec![],
             };

src/meta/client/src/lib.rs

@@ -117,6 +117,10 @@ pub static METACLI_COMMIT_SEMVER: LazyLock<Version> = LazyLock::new(|| {
 ///   🖥 server: add `txn_condition::Target::KeysWithPrefix`,
 ///              to support matching the key count by a prefix.
 ///
+/// - 2024-12-1*: since 1.2.*
+///   🖥 server: add `TxnRequest::condition_tree`,
+///              to specify a complex bool expression.
+///
 ///
 /// Server feature set:
 /// ```yaml

src/meta/kvapi/Cargo.toml

@@ -15,6 +15,7 @@ test = true
 [dependencies]
 anyhow = { workspace = true }
 async-trait = { workspace = true }
+databend-common-base = { workspace = true }
 databend-common-meta-types = { workspace = true }
 fastrace = { workspace = true }
 futures-util = { workspace = true }