[performance] filter model and database table improvements (#4277)

- removes unnecessary fields / columns (created_at, updated_at)
- replaces filter.context_* columns with singular filter.contexts bit field which should save both struct memory and database space
- replaces filter.action string with integer enum type which should save both struct memory and database space
- adds links from filter to filter_* tables with Filter{}.KeywordIDs and Filter{}.StatusIDs fields (this also means we now have those ID slices cached, which reduces some lookups)
- removes account_id fields from filter_* tables, since there's a more direct connection between filter and filter_* tables, and filter.account_id already exists
- refactors a bunch of the filter processor logic to save on code repetition, factor in the above changes, fix a few bugs with missed error returns and bring it more in-line with some of our newer code

Reviewed-on: https://codeberg.org/superseriousbusiness/gotosocial/pulls/4277
Co-authored-by: kim <grufwub@gmail.com>
Co-committed-by: kim <grufwub@gmail.com>

1 files changed, 184 insertions, 0 deletions

diff --git a/internal/processing/filters/common/common.go b/internal/processing/filters/common/common.go
new file mode 100644
index 000000000..a119d3bd4
--- /dev/null
+++ b/internal/processing/filters/common/common.go
@@ -0,0 +1,184 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package common
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"net/http"
+
+	apimodel "code.superseriousbusiness.org/gotosocial/internal/api/model"
+	"code.superseriousbusiness.org/gotosocial/internal/db"
+	"code.superseriousbusiness.org/gotosocial/internal/gtscontext"
+	"code.superseriousbusiness.org/gotosocial/internal/gtserror"
+	"code.superseriousbusiness.org/gotosocial/internal/gtsmodel"
+	"code.superseriousbusiness.org/gotosocial/internal/state"
+)
+
+type Processor struct{ state *state.State }
+
+func New(state *state.State) *Processor { return &Processor{state} }
+
+// CheckFilterExists calls .GetFilter() with a barebones context to not
+// fetch any sub-models, and not returning the result. this functionally
+// just uses .GetFilter() for the ownership and existence checks.
+func (p *Processor) CheckFilterExists(
+	ctx context.Context,
+	requester *gtsmodel.Account,
+	id string,
+) gtserror.WithCode {
+	_, errWithCode := p.GetFilter(gtscontext.SetBarebones(ctx), requester, id)
+	return errWithCode
+}
+
+// GetFilter fetches the filter with given ID, also checking
+// the given requesting account is the owner of the filter.
+func (p *Processor) GetFilter(
+	ctx context.Context,
+	requester *gtsmodel.Account,
+	id string,
+) (
+	*gtsmodel.Filter,
+	gtserror.WithCode,
+) {
+	// Get the filter from the database with given ID.
+	filter, err := p.state.DB.GetFilterByID(ctx, id)
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
+		err := gtserror.Newf("error getting filter: %w", err)
+		return nil, gtserror.NewErrorInternalError(err)
+	}
+
+	// Check it exists.
+	if filter == nil {
+		const text = "filter not found"
+		return nil, gtserror.NewWithCode(http.StatusNotFound, text)
+	}
+
+	// Check that the requester owns it.
+	if filter.AccountID != requester.ID {
+		const text = "filter not found"
+		err := gtserror.New("filter does not belong to account")
+		return nil, gtserror.NewErrorNotFound(err, text)
+	}
+
+	return filter, nil
+}
+
+// GetFilterStatus fetches the filter status with given ID, also
+// checking the given requesting account is the owner of it.
+func (p *Processor) GetFilterStatus(
+	ctx context.Context,
+	requester *gtsmodel.Account,
+	id string,
+) (
+	*gtsmodel.FilterStatus,
+	*gtsmodel.Filter,
+	gtserror.WithCode,
+) {
+
+	// Get the filter status from the database with given ID.
+	filterStatus, err := p.state.DB.GetFilterStatusByID(ctx, id)
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
+		err := gtserror.Newf("error getting filter status: %w", err)
+		return nil, nil, gtserror.NewErrorInternalError(err)
+	}
+
+	// Check it even exists.
+	if filterStatus == nil {
+		const text = "filter status not found"
+		return nil, nil, gtserror.NewWithCode(http.StatusNotFound, text)
+	}
+
+	// Get the filter this filter status is
+	// associated with, without sub-models.
+	// (this also checks filter ownership).
+	filter, errWithCode := p.GetFilter(
+		gtscontext.SetBarebones(ctx),
+		requester,
+		filterStatus.FilterID,
+	)
+	if errWithCode != nil {
+		return nil, nil, errWithCode
+	}
+
+	return filterStatus, filter, nil
+}
+
+// GetFilterKeyword fetches the filter keyword with given ID,
+// also checking the given requesting account is the owner of it.
+func (p *Processor) GetFilterKeyword(
+	ctx context.Context,
+	requester *gtsmodel.Account,
+	id string,
+) (
+	*gtsmodel.FilterKeyword,
+	*gtsmodel.Filter,
+	gtserror.WithCode,
+) {
+
+	// Get the filter keyword from the database with given ID.
+	keyword, err := p.state.DB.GetFilterKeywordByID(ctx, id)
+	if err != nil && !errors.Is(err, db.ErrNoEntries) {
+		err := gtserror.Newf("error getting filter keyword: %w", err)
+		return nil, nil, gtserror.NewErrorInternalError(err)
+	}
+
+	// Check it exists.
+	if keyword == nil {
+		const text = "filter keyword not found"
+		return nil, nil, gtserror.NewWithCode(http.StatusNotFound, text)
+	}
+
+	// Get the filter this filter keyword is
+	// associated with, without sub-models.
+	// (this also checks filter ownership).
+	filter, errWithCode := p.GetFilter(
+		gtscontext.SetBarebones(ctx),
+		requester,
+		keyword.FilterID,
+	)
+	if errWithCode != nil {
+		return nil, nil, errWithCode
+	}
+
+	return keyword, filter, nil
+}
+
+// FromAPIContexts converts a slice of frontend API model FilterContext types to our internal FilterContexts bit field.
+func FromAPIContexts(apiContexts []apimodel.FilterContext) (gtsmodel.FilterContexts, gtserror.WithCode) {
+	var contexts gtsmodel.FilterContexts
+	for _, context := range apiContexts {
+		switch context {
+		case apimodel.FilterContextHome:
+			contexts.SetHome()
+		case apimodel.FilterContextNotifications:
+			contexts.SetNotifications()
+		case apimodel.FilterContextPublic:
+			contexts.SetPublic()
+		case apimodel.FilterContextThread:
+			contexts.SetThread()
+		case apimodel.FilterContextAccount:
+			contexts.SetAccount()
+		default:
+			text := fmt.Sprintf("unsupported filter context: %s", context)
+			return 0, gtserror.NewWithCode(http.StatusBadRequest, text)
+		}
+	}
+	return contexts, nil
+}