Add pprof server on 6060 and /debug route

Author: brlane-rht

internal/dnfjson/cache.go

@@ -1,6 +1,8 @@
 package dnfjson
 
 import (
+	"bytes"
+	"encoding/gob"
 	"fmt"
 	"io/fs"
 	"os"
@@ -213,8 +215,8 @@ func dirSize(path string) (uint64, error) {
 // dnfResults holds the results of a dnfjson request
 // expire is the time the request was made, used to expire the entry
 type dnfResults struct {
-	expire time.Time
-	pkgs   rpmmd.PackageList
+	Expire time.Time
+	Pkgs   rpmmd.PackageList
 }
 
 // dnfCache is a cache of results from dnf-json requests
@@ -241,7 +243,7 @@ func (d *dnfCache) CleanCache() {
 
 	// Delete expired resultCache entries
 	for k := range d.results {
-		if time.Since(d.results[k].expire) > d.timeout {
+		if time.Since(d.results[k].Expire) > d.timeout {
 			delete(d.results, k)
 		}
 	}
@@ -254,15 +256,32 @@ func (d *dnfCache) Get(hash string) (rpmmd.PackageList, bool) {
 	defer d.RUnlock()
 
 	result, ok := d.results[hash]
-	if !ok || time.Since(result.expire) >= d.timeout {
+	if !ok || time.Since(result.Expire) >= d.timeout {
 		return rpmmd.PackageList{}, false
 	}
-	return result.pkgs, true
+	return result.Pkgs, true
 }
 
 // Store saves the package list in the cache
 func (d *dnfCache) Store(hash string, pkgs rpmmd.PackageList) {
 	d.Lock()
 	defer d.Unlock()
-	d.results[hash] = dnfResults{expire: time.Now(), pkgs: pkgs}
+	d.results[hash] = dnfResults{Expire: time.Now(), Pkgs: pkgs}
+}
+
+// Info returns about about the cache
+func (d *dnfCache) Info() map[string]string {
+
+	m := make(map[string]string)
+	m["timeout"] = fmt.Sprintf("%d", d.timeout)
+	m["entries"] = fmt.Sprintf("%d", len(d.results))
+
+	// Try to guesstimate the amount of memory used by marshaling the cache into a byte stream
+	b := new(bytes.Buffer)
+	if err := gob.NewEncoder(b).Encode(d.results); err != nil {
+		m["error"] = err.Error()
+	} else {
+		m["size"] = fmt.Sprintf("%d", b.Len())
+	}
+	return m
 }

internal/dnfjson/dnfjson.go

@@ -111,6 +111,10 @@ func NewSolver(modulePlatformID string, releaseVer string, arch string, cacheDir
 	return s.NewWithConfig(modulePlatformID, releaseVer, arch)
 }
 
+func (s *Solver) CacheDebugInfo() map[string]string {
+	return s.BaseSolver.resultCache.Info()
+}
+
 // Depsolve the list of required package sets with explicit excludes using
 // their associated repositories.  Each package set is depsolved as a separate
 // transactions in a chain.  It returns a list of all packages (with solved

internal/weldr/api.go

@@ -25,6 +25,8 @@ import (
 	"strings"
 	"time"
 
+	_ "net/http/pprof" //nolint:gosec
+
 	"github.com/BurntSushi/toml"
 	"github.com/gobwas/glob"
 	"github.com/google/uuid"
@@ -201,6 +203,12 @@ func New(repoPaths []string, stateDir string, solver *dnfjson.BaseSolver, dr *di
 		distros:                  validDistros(rr, dr, archName, logger),
 		distrosImageTypeDenylist: distrosImageTypeDenylist,
 	}
+
+	// XXX BCL
+	go func() {
+		log.Println(http.ListenAndServe("localhost:6060", nil))
+	}()
+
 	return setupRouter(api), nil
 }
 
@@ -212,6 +220,7 @@ func setupRouter(api *API) *API {
 	api.router.NotFound = http.HandlerFunc(notFoundHandler)
 
 	api.router.GET("/api/status", api.statusHandler)
+	api.router.GET("/api/debug", api.debugHandler)
 	api.router.GET("/api/v:version/projects/source/list", api.sourceListHandler)
 	api.router.GET("/api/v:version/projects/source/info/", api.sourceEmptyInfoHandler)
 	api.router.GET("/api/v:version/projects/source/info/:sources", api.sourceInfoHandler)
@@ -611,6 +620,34 @@ func (api *API) statusHandler(writer http.ResponseWriter, request *http.Request,
 	common.PanicOnError(err)
 }
 
+func (api *API) debugHandler(writer http.ResponseWriter, request *http.Request, _ httprouter.Params) {
+
+	distroName, err := api.parseDistro(request.URL.Query())
+	if err != nil {
+		errors := responseError{
+			ID:  "DistroError",
+			Msg: err.Error(),
+		}
+		statusResponseError(writer, http.StatusBadRequest, errors)
+		return
+	}
+
+	d := api.getDistro(distroName)
+	if d == nil {
+		errors := responseError{
+			ID:  "DistroError",
+			Msg: fmt.Sprintf("GetDistro - unknown distribution: %s", distroName),
+		}
+		statusResponseError(writer, http.StatusBadRequest, errors)
+		return
+	}
+
+	solver := api.solver.NewWithConfig(d.ModulePlatformID(), d.Releasever(), api.archName)
+	info := solver.CacheDebugInfo()
+	err = json.NewEncoder(writer).Encode(info)
+	common.PanicOnError(err)
+}
+
 func (api *API) sourceListHandler(writer http.ResponseWriter, request *http.Request, params httprouter.Params) {
 	if !verifyRequestVersion(writer, params, 0) {
 		return