From c3b4828a5c294cb81e8347e265c9bcd784bf89a5 Mon Sep 17 00:00:00 2001
From: Travis Ralston <travpc@gmail.com>
Date: Tue, 4 Jul 2023 22:11:27 -0600
Subject: [PATCH] Implement new URL preview pipeline engine
---
api/r0/preview_url.go | 31 +++--
database/db.go | 4 +
database/table_url_previews.go | 84 ++++++++++++
pipelines/_steps/url_preview/upload_image.go | 67 ++++++++++
pipelines/pipeline_preview/pipeline.go | 127 +++++++++++++++++++
util/time.go | 4 +
6 files changed, 308 insertions(+), 9 deletions(-)
create mode 100644 database/table_url_previews.go
create mode 100644 pipelines/_steps/url_preview/upload_image.go
create mode 100644 pipelines/pipeline_preview/pipeline.go
diff --git a/api/r0/preview_url.go b/api/r0/preview_url.go
index c761a4f0..2f42a291 100644
--- a/api/r0/preview_url.go
+++ b/api/r0/preview_url.go
@@ -1,17 +1,18 @@
package r0
import (
- "github.com/getsentry/sentry-go"
- "github.com/turt2live/matrix-media-repo/api/_apimeta"
- "github.com/turt2live/matrix-media-repo/api/_responses"
-
+ "errors"
"net/http"
"strconv"
"strings"
+ "github.com/getsentry/sentry-go"
+ "github.com/turt2live/matrix-media-repo/api/_apimeta"
+ "github.com/turt2live/matrix-media-repo/api/_responses"
+ "github.com/turt2live/matrix-media-repo/pipelines/pipeline_preview"
+
"github.com/turt2live/matrix-media-repo/common"
"github.com/turt2live/matrix-media-repo/common/rcontext"
- "github.com/turt2live/matrix-media-repo/controllers/preview_controller"
"github.com/turt2live/matrix-media-repo/util"
)
@@ -61,7 +62,19 @@ func PreviewUrl(r *http.Request, rctx rcontext.RequestContext, user _apimeta.Use
languageHeader = r.Header.Get("Accept-Language")
}
- preview, err := preview_controller.GetPreview(urlStr, r.Host, user.UserId, ts, languageHeader, rctx)
+ preview, err := pipeline_preview.Execute(rctx, r.Host, urlStr, user.UserId, pipeline_preview.PreviewOpts{
+ Timestamp: ts,
+ LanguageHeader: languageHeader,
+ })
+ if err == nil && preview != nil && preview.ErrorCode != "" {
+ if preview.ErrorCode == common.ErrCodeInvalidHost {
+ err = common.ErrInvalidHost
+ } else if preview.ErrorCode == common.ErrCodeNotFound {
+ err = common.ErrMediaNotFound
+ } else {
+ err = errors.New("url previews: unknown error code: " + preview.ErrorCode)
+ }
+ }
if err != nil {
if err == common.ErrMediaNotFound || err == common.ErrHostNotFound {
return _responses.NotFoundError()
@@ -69,14 +82,14 @@ func PreviewUrl(r *http.Request, rctx rcontext.RequestContext, user _apimeta.Use
return _responses.BadRequest(err.Error())
} else {
sentry.CaptureException(err)
- return _responses.InternalServerError("unexpected error during request")
+ return _responses.InternalServerError("Unexpected Error")
}
}
return &MatrixOpenGraph{
- Url: preview.Url,
+ Url: preview.SiteUrl,
SiteName: preview.SiteName,
- Type: preview.Type,
+ Type: preview.ResourceType,
Description: preview.Description,
Title: preview.Title,
ImageMxc: preview.ImageMxc,
diff --git a/database/db.go b/database/db.go
index d4fbbfa2..e738f566 100644
--- a/database/db.go
+++ b/database/db.go
@@ -24,6 +24,7 @@ type Database struct {
HeldMedia *heldMediaTableStatements
Thumbnails *thumbnailsTableStatements
LastAccess *lastAccessTableStatements
+ UrlPreviews *urlPreviewsTableStatements
}
var instance *Database
@@ -104,6 +105,9 @@ func openDatabase(connectionString string, maxConns int, maxIdleConns int) error
if d.LastAccess, err = prepareLastAccessTables(d.conn); err != nil {
return errors.New("failed to create last access table accessor: " + err.Error())
}
+ if d.UrlPreviews, err = prepareUrlPreviewsTables(d.conn); err != nil {
+ return errors.New("failed to create url previews table accessor: " + err.Error())
+ }
instance = d
return nil
diff --git a/database/table_url_previews.go b/database/table_url_previews.go
new file mode 100644
index 00000000..23514eb9
--- /dev/null
+++ b/database/table_url_previews.go
@@ -0,0 +1,84 @@
+package database
+
+import (
+ "database/sql"
+ "errors"
+
+ "github.com/turt2live/matrix-media-repo/common/rcontext"
+ "github.com/turt2live/matrix-media-repo/util"
+)
+
+type DbUrlPreview struct {
+ Url string
+ ErrorCode string
+ BucketTs int64
+ SiteUrl string
+ SiteName string
+ ResourceType string
+ Description string
+ Title string
+ ImageMxc string
+ ImageType string
+ ImageSize int64
+ ImageWidth int
+ ImageHeight int
+ LanguageHeader string
+}
+
+const selectUrlPreview = "SELECT url, error_code, bucket_ts, site_url, site_name, resource_type, description, title, image_mxc, image_type, image_size, image_width, image_height, language_header FROM url_previews WHERE url = $1 AND bucket_ts = $2 AND language_header = $3;"
+const insertUrlPreview = "INSERT INTO url_previews (url, error_code, bucket_ts, site_url, site_name, resource_type, description, title, image_mxc, image_type, image_size, image_width, image_height, language_header) VALUES ($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13, $14);"
+
+type urlPreviewsTableStatements struct {
+ selectUrlPreview *sql.Stmt
+ insertUrlPreview *sql.Stmt
+}
+
+type urlPreviewsTableWithContext struct {
+ statements *urlPreviewsTableStatements
+ ctx rcontext.RequestContext
+}
+
+func prepareUrlPreviewsTables(db *sql.DB) (*urlPreviewsTableStatements, error) {
+ var err error
+ var stmts = &urlPreviewsTableStatements{}
+
+ if stmts.selectUrlPreview, err = db.Prepare(selectUrlPreview); err != nil {
+ return nil, errors.New("error preparing selectUrlPreview: " + err.Error())
+ }
+ if stmts.insertUrlPreview, err = db.Prepare(insertUrlPreview); err != nil {
+ return nil, errors.New("error preparing insertUrlPreview: " + err.Error())
+ }
+
+ return stmts, nil
+}
+
+func (s *urlPreviewsTableStatements) Prepare(ctx rcontext.RequestContext) *urlPreviewsTableWithContext {
+ return &urlPreviewsTableWithContext{
+ statements: s,
+ ctx: ctx,
+ }
+}
+
+func (s *urlPreviewsTableWithContext) Get(url string, ts int64, languageHeader string) (*DbUrlPreview, error) {
+ row := s.statements.selectUrlPreview.QueryRowContext(s.ctx, url, ts, languageHeader)
+ val := &DbUrlPreview{}
+ err := row.Scan(&val.Url, &val.ErrorCode, &val.BucketTs, &val.SiteUrl, &val.SiteName, &val.ResourceType, &val.Description, &val.Title, &val.ImageMxc, &val.ImageType, &val.ImageSize, &val.ImageWidth, &val.ImageHeight, &val.LanguageHeader)
+ if err == sql.ErrNoRows {
+ return nil, nil
+ }
+ return val, err
+}
+
+func (s *urlPreviewsTableWithContext) Insert(p *DbUrlPreview) error {
+ _, err := s.statements.insertUrlPreview.ExecContext(s.ctx, p.Url, p.ErrorCode, p.BucketTs, p.SiteUrl, p.SiteName, p.ResourceType, p.Description, p.Title, p.ImageMxc, p.ImageType, p.ImageSize, p.ImageWidth, p.ImageHeight, p.LanguageHeader)
+ return err
+}
+
+func (s *urlPreviewsTableWithContext) InsertError(url string, errorCode string) {
+ _ = s.Insert(&DbUrlPreview{
+ Url: url,
+ ErrorCode: errorCode,
+ BucketTs: util.GetHourBucket(util.NowMillis()),
+ // remainder of fields don't matter
+ })
+}
diff --git a/pipelines/_steps/url_preview/upload_image.go b/pipelines/_steps/url_preview/upload_image.go
new file mode 100644
index 00000000..4694c925
--- /dev/null
+++ b/pipelines/_steps/url_preview/upload_image.go
@@ -0,0 +1,67 @@
+package url_preview
+
+import (
+ "io"
+
+ "github.com/getsentry/sentry-go"
+ "github.com/turt2live/matrix-media-repo/common/rcontext"
+ "github.com/turt2live/matrix-media-repo/controllers/preview_controller/preview_types"
+ "github.com/turt2live/matrix-media-repo/database"
+ "github.com/turt2live/matrix-media-repo/datastores"
+ "github.com/turt2live/matrix-media-repo/pipelines/pipeline_upload"
+ "github.com/turt2live/matrix-media-repo/thumbnailing"
+ "github.com/turt2live/matrix-media-repo/util"
+)
+
+func UploadImage(ctx rcontext.RequestContext, image *preview_types.PreviewImage, onHost string, userId string, forRecord *database.DbUrlPreview) {
+ if image == nil {
+ return
+ }
+
+ pr, pw := io.Pipe()
+ tee := io.TeeReader(image.Data, pw)
+ mediaChan := make(chan *database.DbMedia)
+ defer close(mediaChan)
+ go func() {
+ media, err := pipeline_upload.Execute(ctx, onHost, "", io.NopCloser(tee), image.ContentType, image.Filename, userId, datastores.LocalMediaKind)
+ if err != nil {
+ _ = pw.CloseWithError(err)
+ } else {
+ _ = pw.Close()
+ }
+ go func() {
+ defer func() {
+ recover() // consume write-to-closed-channel errors
+ }()
+ mediaChan <- media
+ }()
+ }()
+
+ w := 0
+ h := 0
+ g, r, err := thumbnailing.GetGenerator(pr, image.ContentType, false)
+ _, _ = io.Copy(io.Discard, pr)
+ if err != nil {
+ ctx.Log.Warn("Non-fatal error handling URL preview thumbnail: ", err)
+ sentry.CaptureException(err)
+ return
+ }
+ if g != nil {
+ _, w, h, err = g.GetOriginDimensions(r, image.ContentType, ctx)
+ if err != nil {
+ ctx.Log.Warn("Non-fatal error getting URL preview thumbnail dimensions: ", err)
+ sentry.CaptureException(err)
+ }
+ }
+
+ record := <-mediaChan
+ if record == nil {
+ return
+ }
+
+ forRecord.ImageMxc = util.MxcUri(record.Origin, record.MediaId)
+ forRecord.ImageType = record.ContentType
+ forRecord.ImageSize = record.SizeBytes
+ forRecord.ImageWidth = w
+ forRecord.ImageHeight = h
+}
diff --git a/pipelines/pipeline_preview/pipeline.go b/pipelines/pipeline_preview/pipeline.go
new file mode 100644
index 00000000..330428ac
--- /dev/null
+++ b/pipelines/pipeline_preview/pipeline.go
@@ -0,0 +1,127 @@
+package pipeline_preview
+
+import (
+ "errors"
+ "fmt"
+ "net/url"
+
+ "github.com/getsentry/sentry-go"
+ "github.com/turt2live/matrix-media-repo/common"
+ "github.com/turt2live/matrix-media-repo/common/rcontext"
+ "github.com/turt2live/matrix-media-repo/controllers/preview_controller/preview_types"
+ "github.com/turt2live/matrix-media-repo/controllers/preview_controller/previewers"
+ "github.com/turt2live/matrix-media-repo/database"
+ "github.com/turt2live/matrix-media-repo/pipelines/_steps/url_preview"
+ "github.com/turt2live/matrix-media-repo/util"
+ "golang.org/x/sync/singleflight"
+)
+
+var sf = new(singleflight.Group)
+
+type PreviewOpts struct {
+ Timestamp int64
+ LanguageHeader string
+}
+
+func Execute(ctx rcontext.RequestContext, onHost string, previewUrl string, userId string, opts PreviewOpts) (*database.DbUrlPreview, error) {
+ // Step 1: Check database cache
+ previewDb := database.GetInstance().UrlPreviews.Prepare(ctx)
+ record, err := previewDb.Get(previewUrl, opts.Timestamp, opts.LanguageHeader)
+ if err != nil || record != nil {
+ return record, err
+ }
+
+ // Step 2: Fix timestamp bucket. If we're within 60 seconds of a bucket, just assume we're okay, so we don't
+ // infinitely recurse into ourselves.
+ now := util.NowMillis()
+ atBucket := util.GetHourBucket(opts.Timestamp)
+ nowBucket := util.GetHourBucket(now)
+ if (now-opts.Timestamp) > 60000 && atBucket != nowBucket {
+ return Execute(ctx, onHost, previewUrl, userId, PreviewOpts{
+ Timestamp: now,
+ LanguageHeader: opts.LanguageHeader,
+ })
+ }
+
+ // Step 3: Process the URL
+ parsedUrl, err := url.Parse(previewUrl)
+ if err != nil {
+ previewDb.InsertError(previewUrl, common.ErrCodeInvalidHost)
+ return nil, common.ErrInvalidHost
+ }
+ parsedUrl.Fragment = "" // remove fragments because they're not useful to servers
+
+ // Step 4: Join the singleflight queue
+ r, err, _ := sf.Do(fmt.Sprintf("%s:%s_%d/%s", onHost, previewUrl, opts.Timestamp, opts.LanguageHeader), func() (interface{}, error) {
+ payload := &preview_types.UrlPayload{
+ UrlString: previewUrl,
+ ParsedUrl: parsedUrl,
+ }
+ var preview preview_types.PreviewResult
+ err = preview_types.ErrPreviewUnsupported
+
+ // Step 5: Try oEmbed
+ if ctx.Config.UrlPreviews.OEmbed {
+ ctx.Log.Debug("Trying oEmbed previewer")
+ preview, err = previewers.GenerateOEmbedPreview(payload, opts.LanguageHeader, ctx)
+ }
+
+ // Step 6: Try OpenGraph
+ if err == preview_types.ErrPreviewUnsupported {
+ ctx.Log.Debug("Trying OpenGraph previewer")
+ preview, err = previewers.GenerateOpenGraphPreview(payload, opts.LanguageHeader, ctx)
+ }
+
+ // Step 7: Try scraping
+ if err == preview_types.ErrPreviewUnsupported {
+ ctx.Log.Debug("Trying built-in previewer")
+ preview, err = previewers.GenerateCalculatedPreview(payload, opts.LanguageHeader, ctx)
+ }
+
+ // Step 8: Finish processing
+ if err != nil {
+ if err == preview_types.ErrPreviewUnsupported {
+ err = common.ErrMediaNotFound
+ }
+
+ if err == common.ErrMediaNotFound {
+ previewDb.InsertError(previewUrl, common.ErrCodeNotFound)
+ } else {
+ previewDb.InsertError(previewUrl, common.ErrCodeUnknown)
+ }
+ return nil, err
+ } else {
+ result := &database.DbUrlPreview{
+ Url: previewUrl,
+ ErrorCode: "",
+ BucketTs: util.GetHourBucket(opts.Timestamp),
+ SiteUrl: preview.Url,
+ SiteName: preview.SiteName,
+ ResourceType: preview.Type,
+ Description: preview.Description,
+ Title: preview.Title,
+ LanguageHeader: opts.LanguageHeader,
+ }
+
+ // Step 9: Store the thumbnail, if needed
+ url_preview.UploadImage(ctx, preview.Image, onHost, userId, result)
+
+ // Step 10: Insert the record
+ err = previewDb.Insert(result)
+ if err != nil {
+ ctx.Log.Warn("Non-fatal error caching URL preview: ", err)
+ sentry.CaptureException(err)
+ }
+
+ return result, nil
+ }
+ })
+ if err != nil {
+ return nil, err
+ }
+ if val, ok := r.(*database.DbUrlPreview); !ok {
+ return nil, errors.New("runtime error: expected DbUrlPreview, got something else")
+ } else {
+ return val, nil
+ }
+}
diff --git a/util/time.go b/util/time.go
index d972bafb..2b8d5a30 100644
--- a/util/time.go
+++ b/util/time.go
@@ -30,3 +30,7 @@ func CalcBlockForDuration(timeoutMs string) (time.Duration, error) {
}
return blockFor, nil
}
+
+func GetHourBucket(ts int64) int64 {
+ return (ts / 3600000) * 3600000
+}
--
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