[performance] cache recently allowed/denied domains to cut down on db calls (#794)

* fetch creation and fetching domain blocks from db

Signed-off-by: kim <grufwub@gmail.com>

* add separate domainblock cache type, handle removing block from cache on delete

Signed-off-by: kim <grufwub@gmail.com>

* fix sentinel nil values being passed into cache

Signed-off-by: kim <grufwub@gmail.com>

Signed-off-by: kim <grufwub@gmail.com>

internal/db/bundb/domain.go

@@ -20,59 +20,134 @@ package bundb
 
 import (
 	"context"
+	"database/sql"
 	"net/url"
 	"strings"
 
+	"github.com/superseriousbusiness/gotosocial/internal/cache"
 	"github.com/superseriousbusiness/gotosocial/internal/config"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
 	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
-	"github.com/superseriousbusiness/gotosocial/internal/util"
 )
 
 type domainDB struct {
-	conn *DBConn
+	conn  *DBConn
+	cache *cache.DomainBlockCache
 }
 
-func (d *domainDB) IsDomainBlocked(ctx context.Context, domain string) (bool, db.Error) {
-	if domain == "" || domain == config.GetHost() {
-		return false, nil
+func (d *domainDB) CreateDomainBlock(ctx context.Context, block gtsmodel.DomainBlock) db.Error {
+	// Normalize to lowercase
+	block.Domain = strings.ToLower(block.Domain)
+
+	// Attempt to insert new domain block
+	_, err := d.conn.NewInsert().
+		Model(&block).
+		Exec(ctx, &block)
+	if err != nil {
+		return d.conn.ProcessError(err)
 	}
 
+	// Cache this domain block
+	d.cache.Put(block.Domain, &block)
+
+	return nil
+}
+
+func (d *domainDB) GetDomainBlock(ctx context.Context, domain string) (*gtsmodel.DomainBlock, db.Error) {
+	// Normalize to lowercase
+	domain = strings.ToLower(domain)
+
+	// Check for easy case, domain referencing *us*
+	if domain == "" || domain == config.GetAccountDomain() {
+		return nil, db.ErrNoEntries
+	}
+
+	// Check for already cached rblock
+	if block, ok := d.cache.GetByDomain(domain); ok {
+		// A 'nil' return value is a sentinel value for no block
+		if block == nil {
+			return nil, db.ErrNoEntries
+		}
+
+		// Else, this block exists
+		return block, nil
+	}
+
+	block := &gtsmodel.DomainBlock{}
+
 	q := d.conn.
 		NewSelect().
-		Model(&gtsmodel.DomainBlock{}).
-		ExcludeColumn("id", "created_at", "updated_at", "created_by_account_id", "private_comment", "public_comment", "obfuscate", "subscription_id").
+		Model(block).
 		Where("domain = ?", domain).
 		Limit(1)
 
-	return d.conn.Exists(ctx, q)
+	// Query database for domain block
+	switch err := q.Scan(ctx); err {
+	// No error, block found
+	case nil:
+		d.cache.Put(domain, block)
+		return block, nil
+
+	// No error, simply not found
+	case sql.ErrNoRows:
+		d.cache.Put(domain, nil)
+		return nil, db.ErrNoEntries
+
+	// Any other db error
+	default:
+		return nil, d.conn.ProcessError(err)
+	}
+}
+
+func (d *domainDB) DeleteDomainBlock(ctx context.Context, domain string) db.Error {
+	// Normalize to lowercase
+	domain = strings.ToLower(domain)
+
+	// Attempt to delete domain block
+	_, err := d.conn.NewDelete().
+		Model((*gtsmodel.DomainBlock)(nil)).
+		Where("domain = ?", domain).
+		Exec(ctx, nil)
+	if err != nil {
+		return d.conn.ProcessError(err)
+	}
+
+	// Clear domain from cache
+	d.cache.InvalidateByDomain(domain)
+
+	return nil
+}
+
+func (d *domainDB) IsDomainBlocked(ctx context.Context, domain string) (bool, db.Error) {
+	block, err := d.GetDomainBlock(ctx, domain)
+	if err == nil || err == db.ErrNoEntries {
+		return (block != nil), nil
+	}
+	return false, err
 }
 
 func (d *domainDB) AreDomainsBlocked(ctx context.Context, domains []string) (bool, db.Error) {
-	// filter out any doubles
-	uniqueDomains := util.UniqueStrings(domains)
-
-	for _, domain := range uniqueDomains {
-		if blocked, err := d.IsDomainBlocked(ctx, strings.ToLower(domain)); err != nil {
+	for _, domain := range domains {
+		if blocked, err := d.IsDomainBlocked(ctx, domain); err != nil {
 			return false, err
 		} else if blocked {
 			return blocked, nil
 		}
 	}
-
-	// no blocks found
 	return false, nil
 }
 
 func (d *domainDB) IsURIBlocked(ctx context.Context, uri *url.URL) (bool, db.Error) {
-	domain := uri.Hostname()
-	return d.IsDomainBlocked(ctx, domain)
+	return d.IsDomainBlocked(ctx, uri.Hostname())
 }
 
 func (d *domainDB) AreURIsBlocked(ctx context.Context, uris []*url.URL) (bool, db.Error) {
-	domains := []string{}
 	for _, uri := range uris {
-		domains = append(domains, uri.Hostname())
+		if blocked, err := d.IsDomainBlocked(ctx, uri.Hostname()); err != nil {
+			return false, err
+		} else if blocked {
+			return blocked, nil
+		}
 	}
-	return d.AreDomainsBlocked(ctx, domains)
+	return false, nil
 }