github.com/dolthub/dolt/go@v0.40.5-0.20240520175717-68db7794bea6/libraries/doltcore/sqle/dprocedures/stats_funcs.go (about)

     1  // Copyright 2024 Dolthub, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package dprocedures
    16  
    17  import (
    18  	"fmt"
    19  	"strings"
    20  
    21  	"github.com/dolthub/go-mysql-server/sql"
    22  	gmstypes "github.com/dolthub/go-mysql-server/sql/types"
    23  
    24  	"github.com/dolthub/dolt/go/libraries/doltcore/env"
    25  	"github.com/dolthub/dolt/go/libraries/doltcore/ref"
    26  	"github.com/dolthub/dolt/go/libraries/doltcore/sqle/dsess"
    27  )
    28  
    29  var statsFuncSchema = []*sql.Column{
    30  	{
    31  		Name:     "message",
    32  		Type:     gmstypes.LongText,
    33  		Nullable: true,
    34  	},
    35  }
    36  
    37  func statsFunc(fn func(ctx *sql.Context) (interface{}, error)) func(ctx *sql.Context, args ...string) (sql.RowIter, error) {
    38  	return func(ctx *sql.Context, args ...string) (sql.RowIter, error) {
    39  		res, err := fn(ctx)
    40  		if err != nil {
    41  			return nil, err
    42  		}
    43  		return rowToIter(res), nil
    44  	}
    45  }
    46  
    47  // AutoRefreshStatsProvider is a sql.StatsProvider that exposes hooks for
    48  // observing and manipulating background database auto refresh threads.
    49  type AutoRefreshStatsProvider interface {
    50  	sql.StatsProvider
    51  	CancelRefreshThread(string)
    52  	StartRefreshThread(*sql.Context, dsess.DoltDatabaseProvider, string, *env.DoltEnv, dsess.SqlDatabase) error
    53  	ThreadStatus(string) string
    54  }
    55  
    56  // statsRestart tries to stop and then start a refresh thread
    57  func statsRestart(ctx *sql.Context) (interface{}, error) {
    58  	dSess := dsess.DSessFromSess(ctx.Session)
    59  	statsPro := dSess.StatsProvider()
    60  	dbName := strings.ToLower(ctx.GetCurrentDatabase())
    61  
    62  	if afp, ok := statsPro.(AutoRefreshStatsProvider); ok {
    63  		pro := dSess.Provider()
    64  		newFs, err := pro.FileSystem().WithWorkingDir(dbName)
    65  		if err != nil {
    66  			return nil, fmt.Errorf("failed to restart stats collection: %w", err)
    67  		}
    68  
    69  		dEnv := env.Load(ctx, env.GetCurrentUserHomeDir, newFs, pro.DbFactoryUrl(), "TODO")
    70  
    71  		sqlDb, ok := pro.BaseDatabase(ctx, dbName)
    72  		if !ok {
    73  			return nil, fmt.Errorf("failed to restart stats collection: database not found: %s", dbName)
    74  		}
    75  
    76  		afp.CancelRefreshThread(dbName)
    77  
    78  		err = afp.StartRefreshThread(ctx, pro, dbName, dEnv, sqlDb)
    79  		if err != nil {
    80  			return nil, fmt.Errorf("failed to restart collection: %w", err)
    81  		}
    82  		return fmt.Sprintf("restarted stats collection: %s", ref.StatsRef{}.String()), nil
    83  	}
    84  	return nil, fmt.Errorf("provider does not implement AutoRefreshStatsProvider")
    85  }
    86  
    87  // statsStatus returns the last update for a stats thread
    88  func statsStatus(ctx *sql.Context) (interface{}, error) {
    89  	dSess := dsess.DSessFromSess(ctx.Session)
    90  	dbName := strings.ToLower(ctx.GetCurrentDatabase())
    91  	pro := dSess.StatsProvider()
    92  	if afp, ok := pro.(AutoRefreshStatsProvider); ok {
    93  		return afp.ThreadStatus(dbName), nil
    94  	}
    95  	return nil, fmt.Errorf("provider does not implement AutoRefreshStatsProvider")
    96  }
    97  
    98  // statsStop cancels a refresh thread
    99  func statsStop(ctx *sql.Context) (interface{}, error) {
   100  	dSess := dsess.DSessFromSess(ctx.Session)
   101  	statsPro := dSess.StatsProvider()
   102  	dbName := strings.ToLower(ctx.GetCurrentDatabase())
   103  
   104  	if afp, ok := statsPro.(AutoRefreshStatsProvider); ok {
   105  		afp.CancelRefreshThread(dbName)
   106  		return fmt.Sprintf("stopped thread: %s", dbName), nil
   107  	}
   108  	return nil, fmt.Errorf("provider does not implement AutoRefreshStatsProvider")
   109  }
   110  
   111  // statsDrop deletes the stats ref
   112  func statsDrop(ctx *sql.Context) (interface{}, error) {
   113  	dSess := dsess.DSessFromSess(ctx.Session)
   114  	pro := dSess.StatsProvider()
   115  	dbName := strings.ToLower(ctx.GetCurrentDatabase())
   116  
   117  	if afp, ok := pro.(AutoRefreshStatsProvider); ok {
   118  		// currently unsafe to drop stats while running refresh
   119  		afp.CancelRefreshThread(dbName)
   120  	}
   121  	err := pro.DropDbStats(ctx, dbName, true)
   122  	if err != nil {
   123  		return nil, fmt.Errorf("failed to drop stats: %w", err)
   124  	}
   125  	return fmt.Sprintf("deleted stats ref for %s", dbName), nil
   126  }