blob: 8afefd448d688ae060f47edc7266e72573154fad [file] [log] [blame]
// Copyright 2019 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package postgres
import (
"context"
"database/sql"
"encoding/json"
"errors"
"fmt"
"hash/fnv"
"io"
"runtime"
"sort"
"strings"
"unicode/utf8"
"github.com/lib/pq"
"go.opencensus.io/trace"
"golang.org/x/mod/module"
"golang.org/x/mod/semver"
"golang.org/x/pkgsite/internal"
"golang.org/x/pkgsite/internal/database"
"golang.org/x/pkgsite/internal/derrors"
"golang.org/x/pkgsite/internal/experiment"
"golang.org/x/pkgsite/internal/log"
"golang.org/x/pkgsite/internal/stdlib"
"golang.org/x/pkgsite/internal/version"
)
// InsertModule inserts a version into the database using
// db.saveVersion, along with a search document corresponding to each of its
// packages.
func (db *DB) InsertModule(ctx context.Context, m *internal.Module) (err error) {
defer func() {
if m == nil {
derrors.Wrap(&err, "DB.InsertModule(ctx, nil)")
return
}
derrors.Wrap(&err, "DB.InsertModule(ctx, Module(%q, %q))", m.ModulePath, m.Version)
}()
if err := validateModule(m); err != nil {
return err
}
// The proxy accepts modules with zero commit times, but they are bad.
if m.CommitTime.IsZero() {
return fmt.Errorf("empty commit time: %w", derrors.BadModule)
}
// Compare existing data from the database, and the module to be
// inserted. Rows that currently exist should not be missing from the
// new module. We want to be sure that we will overwrite every row that
// pertains to the module.
if err := db.compareLicenses(ctx, m); err != nil {
return err
}
if err := db.comparePackages(ctx, m); err != nil {
return err
}
if err := db.comparePaths(ctx, m); err != nil {
return err
}
if !db.bypassLicenseCheck {
// If we are not bypassing license checking, remove data for non-redistributable modules.
m.RemoveNonRedistributableData()
}
return db.saveModule(ctx, m)
}
// saveModule inserts a Module into the database along with its packages,
// imports, and licenses. If any of these rows already exist, the module and
// corresponding will be deleted and reinserted.
// If the module is malformed then insertion will fail.
//
// A derrors.InvalidArgument error will be returned if the given module and
// licenses are invalid.
func (db *DB) saveModule(ctx context.Context, m *internal.Module) (err error) {
defer derrors.Wrap(&err, "saveModule(ctx, tx, Module(%q, %q))", m.ModulePath, m.Version)
ctx, span := trace.StartSpan(ctx, "saveModule")
defer span.End()
logMemory(ctx, "at start of saveModule")
return db.db.Transact(ctx, sql.LevelDefault, func(tx *database.DB) error {
moduleID, err := insertModule(ctx, tx, m)
if err != nil {
return err
}
logMemory(ctx, "after insertModule")
if err := insertLicenses(ctx, tx, m, moduleID); err != nil {
return err
}
logMemory(ctx, "after insertLicenses")
if err := legacyInsertPackages(ctx, tx, m); err != nil {
return err
}
logMemory(ctx, "after insertPackages")
if err := insertUnits(ctx, tx, m, moduleID); err != nil {
return err
}
logMemory(ctx, "after insertUnits")
// Obtain a transaction-scoped exclusive advisory lock on the module
// path. The transaction that holds the lock is the only one that can
// execute the subsequent code on any module with the given path. That
// means that conflicts from two transactions both believing they are
// working on the latest version of a given module cannot happen.
// The lock is released automatically at the end of the transaction.
if err := lock(ctx, tx, m.ModulePath); err != nil {
return err
}
// We only insert into imports_unique and search_documents if this is
// the latest version of the module.
isLatest, err := isLatestVersion(ctx, tx, m.ModulePath, m.Version)
if err != nil {
return err
}
if !isLatest {
return nil
}
if err := insertImportsUnique(ctx, tx, m); err != nil {
return err
}
// If there is a more recent version of this module that has an alternative
// module path, then do not insert its packages into search_documents. This
// happens when a module that initially does not have a go.mod file is
// forked or fetched via some non-canonical path (such as an alternative
// capitalization), and then in a later version acquires a go.mod file.
//
// To take an actual example: github.com/sirupsen/logrus@v1.1.0 has a go.mod
// file that establishes that path as canonical. But v1.0.6 does not have a
// go.mod file. So the miscapitalized path github.com/Sirupsen/logrus at
// v1.1.0 is marked as an alternative path (code 491) by
// internal/fetch.FetchModule and is not inserted into the DB, but at
// v1.0.6 it is considered valid, and we end up here. We still insert
// github.com/Sirupsen/logrus@v1.0.6 in the modules table and friends so
// that users who import it can find information about it, but we don't want
// it showing up in search results.
//
// Note that we end up here only if we first saw the alternative version
// (github.com/Sirupsen/logrus@v1.1.0 in the example) and then see the valid
// one. The "if code == 491" section of internal/worker.fetchAndUpdateState
// handles the case where we fetch the versions in the other order.
row := tx.QueryRow(ctx, `
SELECT 1 FROM module_version_states
WHERE module_path = $1 AND sort_version > $2 and status = 491`,
m.ModulePath, version.ForSorting(m.Version))
var x int
if err := row.Scan(&x); err != sql.ErrNoRows {
log.Infof(ctx, "%s@%s: not inserting into search documents", m.ModulePath, m.Version)
return err
}
// Insert the module's packages into search_documents.
return upsertSearchDocuments(ctx, tx, m)
})
}
func insertModule(ctx context.Context, db *database.DB, m *internal.Module) (_ int, err error) {
ctx, span := trace.StartSpan(ctx, "insertModule")
defer span.End()
defer derrors.Wrap(&err, "insertModule(ctx, %q, %q)", m.ModulePath, m.Version)
sourceInfoJSON, err := json.Marshal(m.SourceInfo)
if err != nil {
return 0, err
}
versionType, err := version.ParseType(m.Version)
if err != nil {
return 0, err
}
var moduleID int
err = db.QueryRow(ctx,
`INSERT INTO modules(
module_path,
version,
commit_time,
sort_version,
version_type,
series_path,
source_info,
redistributable,
has_go_mod,
incompatible)
VALUES($1,$2,$3,$4,$5,$6,$7,$8,$9,$10)
ON CONFLICT
(module_path, version)
DO UPDATE SET
source_info=excluded.source_info,
redistributable=excluded.redistributable
RETURNING id`,
m.ModulePath,
m.Version,
m.CommitTime,
version.ForSorting(m.Version),
versionType,
m.SeriesPath(),
sourceInfoJSON,
m.IsRedistributable,
m.HasGoMod,
isIncompatible(m.Version),
).Scan(&moduleID)
if err != nil {
return 0, err
}
return moduleID, nil
}
func insertLicenses(ctx context.Context, db *database.DB, m *internal.Module, moduleID int) (err error) {
ctx, span := trace.StartSpan(ctx, "insertLicenses")
defer span.End()
defer derrors.Wrap(&err, "insertLicenses(ctx, %q, %q)", m.ModulePath, m.Version)
var licenseValues []interface{}
for _, l := range m.Licenses {
covJSON, err := json.Marshal(l.Coverage)
if err != nil {
return fmt.Errorf("marshalling %+v: %v", l.Coverage, err)
}
licenseValues = append(licenseValues, m.ModulePath, m.Version,
l.FilePath, makeValidUnicode(string(l.Contents)), pq.Array(l.Types), covJSON, moduleID)
}
if len(licenseValues) > 0 {
licenseCols := []string{
"module_path",
"version",
"file_path",
"contents",
"types",
"coverage",
"module_id",
}
return db.BulkUpsert(ctx, "licenses", licenseCols, licenseValues,
[]string{"module_path", "version", "file_path"})
}
return nil
}
func legacyInsertPackages(ctx context.Context, db *database.DB, m *internal.Module) (err error) {
ctx, span := trace.StartSpan(ctx, "insertPackages")
defer span.End()
defer derrors.Wrap(&err, "insertPackages(ctx, %q, %q)", m.ModulePath, m.Version)
// Sort to ensure proper lock ordering, avoiding deadlocks. See
// b/141164828#comment8. The only deadlocks we've actually seen are on
// imports_unique, because they can occur when processing two versions of
// the same module, which happens regularly. But if we were ever to process
// the same module and version twice, we could see deadlocks in the other
// bulk inserts.
sort.Slice(m.LegacyPackages, func(i, j int) bool {
return m.LegacyPackages[i].Path < m.LegacyPackages[j].Path
})
sort.Slice(m.Licenses, func(i, j int) bool {
return m.Licenses[i].FilePath < m.Licenses[j].FilePath
})
for _, p := range m.LegacyPackages {
sort.Strings(p.Imports)
}
var pkgValues, importValues []interface{}
for _, p := range m.LegacyPackages {
if p.DocumentationHTML.String() == internal.StringFieldMissing {
return errors.New("saveModule: package missing DocumentationHTML")
}
var licenseTypes, licensePaths []string
for _, l := range p.Licenses {
if len(l.Types) == 0 {
// If a license file has no detected license types, we still need to
// record it as applicable to the package, because we want to fail
// closed (meaning if there is a LICENSE file containing unknown
// licenses, we assume them not to be permissive of redistribution.)
licenseTypes = append(licenseTypes, "")
licensePaths = append(licensePaths, l.FilePath)
} else {
for _, typ := range l.Types {
licenseTypes = append(licenseTypes, typ)
licensePaths = append(licensePaths, l.FilePath)
}
}
}
pkgValues = append(pkgValues,
p.Path,
p.Synopsis,
p.Name,
m.Version,
m.ModulePath,
p.V1Path,
p.IsRedistributable,
makeValidUnicode(p.DocumentationHTML.String()),
pq.Array(licenseTypes),
pq.Array(licensePaths),
p.GOOS,
p.GOARCH,
m.CommitTime,
)
for _, i := range p.Imports {
importValues = append(importValues, p.Path, m.ModulePath, m.Version, i)
}
}
if len(pkgValues) > 0 {
uniqueCols := []string{"path", "module_path", "version"}
pkgCols := []string{
"path",
"synopsis",
"name",
"version",
"module_path",
"v1_path",
"redistributable",
"documentation",
"license_types",
"license_paths",
"goos",
"goarch",
"commit_time",
}
if err := db.BulkUpsert(ctx, "packages", pkgCols, pkgValues, uniqueCols); err != nil {
return err
}
}
if len(importValues) > 0 {
importCols := []string{
"from_path",
"from_module_path",
"from_version",
"to_path",
}
if err := db.BulkUpsert(ctx, "imports", importCols, importValues, importCols); err != nil {
return err
}
}
return nil
}
// insertImportsUnique inserts and removes rows from the imports_unique table. It should only
// be called if the given module's version is the latest.
func insertImportsUnique(ctx context.Context, tx *database.DB, m *internal.Module) (err error) {
ctx, span := trace.StartSpan(ctx, "insertImportsUnique")
defer span.End()
defer derrors.Wrap(&err, "insertImportsUnique(%q, %q)", m.ModulePath, m.Version)
// Remove the previous rows for this module. We'll replace them with
// new ones below.
if _, err := tx.Exec(ctx,
`DELETE FROM imports_unique WHERE from_module_path = $1`,
m.ModulePath); err != nil {
return err
}
var values []interface{}
for _, u := range m.Units {
for _, i := range u.Imports {
values = append(values, u.Path, m.ModulePath, i)
}
}
if len(values) == 0 {
return nil
}
cols := []string{"from_path", "from_module_path", "to_path"}
return tx.BulkUpsert(ctx, "imports_unique", cols, values, cols)
}
func insertUnits(ctx context.Context, db *database.DB, m *internal.Module, moduleID int) (err error) {
defer derrors.Wrap(&err, "insertUnits(ctx, tx, %q, %q)", m.ModulePath, m.Version)
ctx, span := trace.StartSpan(ctx, "insertUnits")
defer span.End()
// Sort to ensure proper lock ordering, avoiding deadlocks. See
// b/141164828#comment8. We have seen deadlocks on package_imports and
// documentation. They can occur when processing two versions of the
// same module, which happens regularly.
sort.Slice(m.Units, func(i, j int) bool {
return m.Units[i].Path < m.Units[j].Path
})
for _, u := range m.Units {
sort.Strings(u.Imports)
}
var (
pathValues []interface{}
paths []string
pathToID = map[string]int{}
pathToReadme = map[string]*internal.Readme{}
pathToDoc = map[string]*internal.Documentation{}
pathToImports = map[string][]string{}
)
for _, d := range m.Units {
var licenseTypes, licensePaths []string
for _, l := range d.Licenses {
if len(l.Types) == 0 {
// If a license file has no detected license types, we still need to
// record it as applicable to the package, because we want to fail
// closed (meaning if there is a LICENSE file containing unknown
// licenses, we assume them not to be permissive of redistribution.)
licenseTypes = append(licenseTypes, "")
licensePaths = append(licensePaths, l.FilePath)
} else {
for _, typ := range l.Types {
licenseTypes = append(licenseTypes, typ)
licensePaths = append(licensePaths, l.FilePath)
}
}
}
pathValues = append(pathValues,
d.Path,
moduleID,
internal.V1Path(d.Path, m.ModulePath),
d.Name,
pq.Array(licenseTypes),
pq.Array(licensePaths),
d.IsRedistributable,
)
if d.Readme != nil {
pathToReadme[d.Path] = d.Readme
}
if d.Documentation != nil && d.Documentation.HTML.String() == internal.StringFieldMissing {
return errors.New("insertUnits: package missing Documentation.HTML")
}
if d.Documentation != nil && experiment.IsActive(ctx, internal.ExperimentInsertPackageSource) {
if d.Documentation.Source == nil {
return fmt.Errorf("insertUnits: unit %q missing source files", d.Path)
}
}
pathToDoc[d.Path] = d.Documentation
if len(d.Imports) > 0 {
pathToImports[d.Path] = d.Imports
}
}
if len(pathValues) > 0 {
pathCols := []string{
"path",
"module_id",
"v1_path",
"name",
"license_types",
"license_paths",
"redistributable",
}
logMemory(ctx, "before inserting into paths")
uniqueCols := []string{"path", "module_id"}
returningCols := []string{"id", "path"}
if err := db.BulkUpsertReturning(ctx, "paths", pathCols, pathValues, uniqueCols, returningCols, func(rows *sql.Rows) error {
var (
pathID int
path string
)
if err := rows.Scan(&pathID, &path); err != nil {
return err
}
pathToID[path] = pathID
paths = append(paths, path)
return nil
}); err != nil {
return err
}
}
// Sort to ensure proper lock ordering, avoiding deadlocks. See
// b/141164828#comment8. We have seen deadlocks on package_imports and
// documentation. They can occur when processing two versions of the
// same module, which happens regularly.
sort.Strings(paths)
if len(pathToReadme) > 0 {
logMemory(ctx, "before inserting into readmes")
var readmeValues []interface{}
for _, path := range paths {
readme, ok := pathToReadme[path]
if !ok {
continue
}
// Do not add a readme with empty or zero contents.
readmeContents := makeValidUnicode(readme.Contents)
if len(readmeContents) == 0 {
continue
}
id := pathToID[path]
readmeValues = append(readmeValues, id, readme.Filepath, readmeContents)
}
readmeCols := []string{"path_id", "file_path", "contents"}
if err := db.BulkUpsert(ctx, "readmes", readmeCols, readmeValues, []string{"path_id"}); err != nil {
return err
}
}
if len(pathToDoc) > 0 {
logMemory(ctx, "before inserting into documentation")
var docValues []interface{}
for _, path := range paths {
doc := pathToDoc[path]
if doc == nil {
continue
}
id := pathToID[path]
docValues = append(docValues, id, doc.GOOS, doc.GOARCH, doc.Synopsis, makeValidUnicode(doc.HTML.String()))
if experiment.IsActive(ctx, internal.ExperimentInsertPackageSource) {
docValues = append(docValues, doc.Source)
}
}
uniqueCols := []string{"path_id", "goos", "goarch"}
docCols := append(uniqueCols, "synopsis", "html")
if experiment.IsActive(ctx, internal.ExperimentInsertPackageSource) {
docCols = append(docCols, "source")
}
if err := db.BulkUpsert(ctx, "documentation", docCols, docValues, uniqueCols); err != nil {
return err
}
}
logMemory(ctx, "before inserting into package_imports")
var importValues []interface{}
for _, pkgPath := range paths {
imports, ok := pathToImports[pkgPath]
if !ok {
continue
}
id := pathToID[pkgPath]
for _, toPath := range imports {
importValues = append(importValues, id, toPath)
}
}
importCols := []string{"path_id", "to_path"}
return db.BulkUpsert(ctx, "package_imports", importCols, importValues, importCols)
}
// lock obtains an exclusive, transaction-scoped advisory lock on modulePath.
func lock(ctx context.Context, tx *database.DB, modulePath string) (err error) {
defer derrors.Wrap(&err, "lock(%s)", modulePath)
if !tx.InTransaction() {
return errors.New("not in a transaction")
}
// Postgres advisory locks use a 64-bit integer key. Convert modulePath to a
// key by hashing.
//
// This can result in collisions (two module paths hashing to the same key),
// but they are unlikely and at worst will slow things down a bit.
//
// We use the FNV hash algorithm from the standard library. It fits into 64
// bits unlike a crypto hash, and is stable across processes, unlike
// hash/maphash.
hasher := fnv.New64()
io.WriteString(hasher, modulePath) // Writing to a hash.Hash never returns an error.
h := int64(hasher.Sum64())
log.Debugf(ctx, "locking %s (%d) ...", modulePath, h)
// See https://www.postgresql.org/docs/11/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS.
if _, err := tx.Exec(ctx, `SELECT pg_advisory_xact_lock($1)`, h); err != nil {
return err
}
log.Debugf(ctx, "locking %s (%d) succeeded", modulePath, h)
return nil
}
// isIncompatible reports whether the build metadata of the version is
// "+incompatible", https://semver.org clause 10.
func isIncompatible(version string) bool {
return strings.HasSuffix(version, "+incompatible")
}
// isLatestVersion reports whether version is the latest version of the module.
func isLatestVersion(ctx context.Context, db *database.DB, modulePath, resolvedVersion string) (_ bool, err error) {
defer derrors.Wrap(&err, "isLatestVersion(ctx, tx, %q)", modulePath)
query := fmt.Sprintf(`
SELECT version FROM modules m WHERE m.module_path = $1
%s
LIMIT 1`, orderByLatest)
row := db.QueryRow(ctx, query, modulePath)
var v string
if err := row.Scan(&v); err != nil {
if err == sql.ErrNoRows {
return true, nil // It's the only version, so it's also the latest.
}
return false, err
}
return resolvedVersion == v, nil
}
// validateModule checks that fields needed to insert a module into the database
// are present. Otherwise, it returns an error listing the reasons the module
// cannot be inserted. Since the problems it looks for are most likely on our
// end, the underlying error it returns is always DBModuleInsertInvalid, meaning
// that this module should be reprocessed.
func validateModule(m *internal.Module) (err error) {
defer func() {
if err != nil {
err = fmt.Errorf("%v: %w", err, derrors.DBModuleInsertInvalid)
if m != nil {
derrors.Wrap(&err, "validateModule(%q, %q)", m.ModulePath, m.Version)
}
}
}()
if m == nil {
return fmt.Errorf("nil module")
}
var errReasons []string
if m.Version == "" {
errReasons = append(errReasons, "no specified version")
}
if m.ModulePath == "" {
errReasons = append(errReasons, "no module path")
}
if m.ModulePath != stdlib.ModulePath {
if err := module.CheckPath(m.ModulePath); err != nil {
errReasons = append(errReasons, fmt.Sprintf("invalid module path (%s)", err))
}
if !semver.IsValid(m.Version) {
errReasons = append(errReasons, "invalid version")
}
}
if len(m.Packages()) == 0 {
errReasons = append(errReasons, "module does not have any packages")
}
if len(errReasons) != 0 {
return fmt.Errorf("cannot insert module %q: %s", m.Version, strings.Join(errReasons, ", "))
}
return nil
}
// compareLicenses compares m.Licenses with the existing licenses for
// m.ModulePath and m.Version in the database. It returns an error if there
// are licenses in the licenses table that are not present in m.Licenses.
func (db *DB) compareLicenses(ctx context.Context, m *internal.Module) (err error) {
defer derrors.Wrap(&err, "compareLicenses(ctx, %q, %q)", m.ModulePath, m.Version)
dbLicenses, err := db.getModuleLicenses(ctx, m.ModulePath, m.Version)
if err != nil {
return err
}
set := map[string]bool{}
for _, l := range m.Licenses {
set[l.FilePath] = true
}
for _, l := range dbLicenses {
if _, ok := set[l.FilePath]; !ok {
return fmt.Errorf("expected license %q in module: %w", l.FilePath, derrors.DBModuleInsertInvalid)
}
}
return nil
}
// comparePackages compares m.LegacyPackages with the existing packages for
// m.ModulePath and m.Version in the database. It returns an error if there
// are packages in the packages table that are not present in m.LegacyPackages.
func (db *DB) comparePackages(ctx context.Context, m *internal.Module) (err error) {
defer derrors.Wrap(&err, "comparePackages(ctx, %q, %q)", m.ModulePath, m.Version)
u, err := db.GetUnit(ctx, &internal.UnitMeta{
ModulePath: m.ModulePath,
Path: m.ModulePath,
Version: m.Version,
IsRedistributable: m.IsRedistributable,
CommitTime: m.CommitTime,
}, internal.WithSubdirectories)
if err != nil {
if errors.Is(err, derrors.NotFound) {
return nil
}
return err
}
set := map[string]bool{}
for _, p := range m.LegacyPackages {
set[p.Path] = true
}
for _, p := range u.Subdirectories {
if _, ok := set[p.Path]; !ok {
return fmt.Errorf("expected package %q in module: %w", p.Path, derrors.DBModuleInsertInvalid)
}
}
return nil
}
// comparePaths compares m.Directories with the existing directories for
// m.ModulePath and m.Version in the database. It returns an error if there
// are paths in the paths table that are not present in m.Directories.
func (db *DB) comparePaths(ctx context.Context, m *internal.Module) (err error) {
defer derrors.Wrap(&err, "comparePaths(ctx, %q, %q)", m.ModulePath, m.Version)
dbPaths, err := db.getPathsInModule(ctx, m.ModulePath, m.Version)
if err != nil {
return err
}
set := map[string]bool{}
for _, p := range m.Units {
set[p.Path] = true
}
for _, p := range dbPaths {
if _, ok := set[p.path]; !ok {
return fmt.Errorf("expected unit %q in module: %w", p.path, derrors.DBModuleInsertInvalid)
}
}
return nil
}
// DeleteModule deletes a Version from the database.
func (db *DB) DeleteModule(ctx context.Context, modulePath, resolvedVersion string) (err error) {
defer derrors.Wrap(&err, "DeleteModule(ctx, db, %q, %q)", modulePath, resolvedVersion)
return db.db.Transact(ctx, sql.LevelDefault, func(tx *database.DB) error {
// We only need to delete from the modules table. Thanks to ON DELETE
// CASCADE constraints, that will trigger deletions from all other tables.
const stmt = `DELETE FROM modules WHERE module_path=$1 AND version=$2`
if _, err := tx.Exec(ctx, stmt, modulePath, resolvedVersion); err != nil {
return err
}
if _, err = tx.Exec(ctx, `DELETE FROM version_map WHERE module_path = $1 AND resolved_version = $2`, modulePath, resolvedVersion); err != nil {
return err
}
var x int
err = tx.QueryRow(ctx, `SELECT 1 FROM modules WHERE module_path=$1 LIMIT 1`, modulePath).Scan(&x)
if err != sql.ErrNoRows || err == nil {
return err
}
// No versions of this module exist; remove it from imports_unique.
_, err = tx.Exec(ctx, `DELETE FROM imports_unique WHERE from_module_path = $1`, modulePath)
return err
})
}
// makeValidUnicode removes null runes from a string that will be saved in a
// column of type TEXT, because pq doesn't like them. It also replaces non-unicode
// characters with the Unicode replacement character, which is the behavior of
// for ... range on strings.
func makeValidUnicode(s string) string {
// If s is valid and has no zeroes, don't copy it.
hasZeroes := false
for _, r := range s {
if r == 0 {
hasZeroes = true
break
}
}
if !hasZeroes && utf8.ValidString(s) {
return s
}
var b strings.Builder
for _, r := range s {
if r != 0 {
b.WriteRune(r)
}
}
return b.String()
}
var MemoryLoggingDisabled = true
func logMemory(ctx context.Context, msg string) {
if !MemoryLoggingDisabled {
log.Debugf(ctx, "memory %s: %dM", msg, allocMeg())
}
}
func allocMeg() int {
var ms runtime.MemStats
runtime.ReadMemStats(&ms)
return int(ms.Alloc / (1024 * 1024))
}