cmd/pkgserver: expose size and store pre-encoded ident

This change also handles SIGSEGV correctly in newStatusHandler, and makes serving status fully zero copy.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/pkgserver/api.go

@@ -1,9 +1,7 @@
 package main
 
 import (
-	"bytes"
 	"encoding/json"
-	"io"
 	"log"
 	"net/http"
 	"path"
@@ -11,7 +9,6 @@ import (
 	"sync"
 
 	"hakurei.app/internal/info"
-	"hakurei.app/internal/pkg"
 	"hakurei.app/internal/rosa"
 )
 
@@ -50,19 +47,27 @@ func (index *packageIndex) newStatusHandler(disposition bool) http.HandlerFunc {
 		if disposition {
 			contentType = "application/octet-stream"
 
+			// quoting like this is unsound, but okay, because metadata is hardcoded
 			contentDisposition := `attachment; filename="`
 			contentDisposition += m.Name + "-"
 			if m.Version != "" {
 				contentDisposition += m.Version + "-"
 			}
-			contentDisposition += pkg.Encode(m.ident.Value()) + `.log"`
+			contentDisposition += m.ids + `.log"`
 			w.Header().Set("Content-Disposition", contentDisposition)
 		}
 		w.Header().Set("Content-Type", contentType)
 		w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
-		_, err := io.Copy(w, bytes.NewReader(m.status))
-		if err != nil {
-			http.Error(w, err.Error(), http.StatusInternalServerError)
+		if err := func() (err error) {
+			defer index.handleAccess(&err)()
+			_, err = w.Write(m.status)
+			return
+		}(); err != nil {
+			log.Println(err)
+			http.Error(
+				w, "cannot deliver status, contact maintainers",
+				http.StatusInternalServerError,
+			)
 		}
 	}
 }

cmd/pkgserver/index.go

@@ -4,7 +4,6 @@ import (
 	"errors"
 	"slices"
 	"strings"
-	"unique"
 
 	"hakurei.app/internal/pkg"
 	"hakurei.app/internal/rosa"
@@ -23,6 +22,9 @@ const (
 type packageIndex struct {
 	sorts [sortOrderEnd + 1][rosa.PresetUnexportedStart]*metadata
 	names map[string]*metadata
+
+	// Taken from [rosa.Report] if available.
+	handleAccess func(*error) func()
 }
 
 // metadata holds [rosa.Metadata] extended with additional information.
@@ -33,11 +35,13 @@ type metadata struct {
 	// Populated via [rosa.Toolchain.Version], [rosa.Unversioned] is equivalent
 	// to the zero value. Otherwise, the zero value is invalid.
 	Version string `json:"version,omitempty"`
+	// Output data size, available if present in report.
+	Size int64 `json:"size,omitempty"`
 	// Whether the underlying [pkg.Artifact] is present in the report.
 	HasReport bool `json:"report"`
 
-	// Ident resolved from underlying [pkg.Artifact].
-	ident unique.Handle[pkg.ID]
+	// Ident string encoded ahead of time.
+	ids string
 	// Backed by [rosa.Report], access must be prepared by HandleAccess.
 	status []byte
 }
@@ -46,6 +50,7 @@ type metadata struct {
 func (index *packageIndex) populate(cache *pkg.Cache, report *rosa.Report) (err error) {
 	if report != nil {
 		defer report.HandleAccess(&err)()
+		index.handleAccess = report.HandleAccess
 	}
 
 	var work [rosa.PresetUnexportedStart]*metadata
@@ -65,12 +70,10 @@ func (index *packageIndex) populate(cache *pkg.Cache, report *rosa.Report) (err
 		}
 
 		if cache != nil && report != nil {
-			m.ident = cache.Ident(rosa.Std.Load(p))
-			status, n := report.ArtifactOf(m.ident)
-			if n >= 0 {
-				m.HasReport = true
-				m.status = status
-			}
+			id := cache.Ident(rosa.Std.Load(p))
+			m.ids = pkg.Encode(id.Value())
+			m.status, m.Size = report.ArtifactOf(id)
+			m.HasReport = m.Size >= 0
 		}
 
 		work[p] = &m