fup: add fngen package, for generating filenames

This commit is contained in:
Luke Granger-Brown 2021-03-21 16:52:53 +00:00
parent de4897da06
commit 691babc0f7
5 changed files with 150 additions and 3 deletions

View file

@ -12,7 +12,7 @@ pkgs.buildGoModule {
src = ./.;
vendorSha256 = "sha256:0jvak2z2f1j9mavzxdqa7jpy3zhzznwyvj10ail7p68yilzbrkja";
vendorSha256 = "sha256:1v9j8wwq9j2njygyn209vzivr6vpdmpdwjivhmjclkyfxq12l0sl";
meta = with pkgs.lib; {
description = "Simple file upload manager.";

View file

@ -0,0 +1,86 @@
// SPDX-FileCopyrightText: 2021 Luke Granger-Brown <depot@lukegb.com>
//
// SPDX-License-Identifier: Apache-2.0
package fngen
import (
"context"
"crypto/rand"
"fmt"
"strings"
petname "github.com/dustinkirkland/golang-petname"
)
// FilenameGenerator generates a new filename based on the provided prefix and extension.
// The full filename, including the provided filenameExt, should be returned.
// attempt will be 0 the first time the filename is generated;
type FilenameGenerator func(filenamePrefix string, filenameExt string, attempt int) string
// IdentityGenerator returns a FilenameGenerator that, on the first attempt, will use the provided filename.
// If it collides with an existing filename, then the provided fallback FilenameGenerator will be used.
func IdentityGenerator(fallback FilenameGenerator) FilenameGenerator {
return func(filenamePrefix string, filenameExt string, attempt int) string {
if attempt > 0 {
return fallback(filenamePrefix, filenameExt, attempt-1)
}
return filenamePrefix + filenameExt
}
}
func init() {
petname.NonDeterministicMode()
}
// PetnameGenerator uses RFC1178 to generate filenames.
// This is sort-of "imgur style".
func PetnameGenerator(filenamePrefix string, filenameExt string, attempt int) string {
bits := strings.Split(petname.Generate(3, "-"), "-")
return fmt.Sprintf("%s%s%s%s",
strings.Title(bits[0]),
strings.Title(bits[1]),
strings.Title(bits[2]),
filenameExt)
}
var boringAlphabet = []byte("0123456789abcdefghijklmnopqrstuvwxyz")
const boringLength = 8
// BoringGenerator just uses a simple lowercase alphabet to generate filenames.
func BoringGenerator(filenamePrefix string, filenameExt string, attempt int) string {
out := make([]byte, boringLength+len(filenameExt))
if _, err := rand.Read(out[:boringLength]); err != nil {
panic(fmt.Sprintf("BoringGenerator's rand.Read: %v", err))
}
for n := 0; n < boringLength; n++ {
out[n] = boringAlphabet[out[n]%byte(len(boringAlphabet))]
}
for n := boringLength; n < boringLength+len(filenameExt); n++ {
out[n] = filenameExt[n-boringLength]
}
return string(out)
}
func uniqueName(ctx context.Context, existsFn func(ctx context.Context, name string) (bool, error), filenamePrefix, extension string, generator FilenameGenerator) (string, error) {
// There's a race condition here, because we might generate a currently-not-taken filename and collide with someone uploading with the same name.
// However, given the usecase of this software, I've decided not to care. I'm unlikely to be uploading enough things concurrently that this is a real issue.
attempt := 0
for {
name := generator(filenamePrefix, extension, attempt)
if name == "" {
return "", fmt.Errorf("filename generator returned the empty string")
}
exists, err := existsFn(ctx, name)
if err != nil {
return "", fmt.Errorf("unable to check for existence of %q: %v", name, err)
}
if !exists {
return name, nil
}
attempt++
}
}

View file

@ -0,0 +1,49 @@
// SPDX-FileCopyrightText: 2021 Luke Granger-Brown <depot@lukegb.com>
//
// SPDX-License-Identifier: Apache-2.0
package fngen_test
import (
"fmt"
"strings"
"testing"
"hg.lukegb.com/lukegb/depot/web/fup/fuphttp/fngen"
)
func TestIdentityGenerator(t *testing.T) {
fallback := func(filenamePrefix string, filenameExt string, attempt int) string {
return fmt.Sprintf("prefix=%s; ext=%s; attempt=%d", filenamePrefix, filenameExt, attempt)
}
gen := fngen.IdentityGenerator(fallback)
if got, want := gen("prefix", ".ext", 0), "prefix.ext"; got != want {
t.Errorf("IdentityGenerator with 0 attempts = %q; want %q", got, want)
}
if got, want := gen("prefix", ".ext", 1), "prefix=prefix; ext=.ext; attempt=0"; got != want {
t.Errorf("IdentityGenerator with 1 attempt = %q; want %q", got, want)
}
if got, want := gen("prefix", ".ext", 2), "prefix=prefix; ext=.ext; attempt=1"; got != want {
t.Errorf("IdentityGenerator with 2 attempts = %q; want %q", got, want)
}
if got, want := gen("prefix", "", 0), "prefix"; got != want {
t.Errorf("IdentityGenerator with no extension = %q; want %q", got, want)
}
}
func TestPetnameGenerator(t *testing.T) {
got := fngen.PetnameGenerator("prefix", ".ext", 0)
if !strings.HasSuffix(got, ".ext") {
t.Errorf("PetnameGenerator(%q, %q, 0) = %q; want something ending in %v", "prefix", ".ext", got, ".ext")
}
}
func TestBoringGenerator(t *testing.T) {
got := fngen.BoringGenerator("prefix", ".ext", 0)
if !strings.HasSuffix(got, ".ext") {
t.Errorf("BoringGenerator(%q, %q, 0) = %q; want something ending in %v", "prefix", ".ext", got, ".ext")
}
}

View file

@ -7,10 +7,11 @@ module hg.lukegb.com/lukegb/depot/web/fup
go 1.16
require (
github.com/dustinkirkland/golang-petname v0.0.0-20191129215211-8e5a1ed0cff0
github.com/google/safehtml v0.0.2
github.com/gorilla/mux v1.8.0
github.com/spf13/cobra v1.1.3
github.com/spf13/viper v1.7.1 // indirect
github.com/spf13/viper v1.7.1
gocloud.dev v0.22.0
golang.org/x/text v0.3.5 // indirect
)

View file

@ -74,6 +74,7 @@ github.com/Azure/go-autorest/autorest/to v0.4.0/go.mod h1:fE8iZBn7LQR7zH/9XU2NcP
github.com/Azure/go-autorest/autorest/validation v0.3.0/go.mod h1:yhLgjC0Wda5DYXl6JAsWyUe4KVNffhoDhG0zVzUMo3E=
github.com/Azure/go-autorest/logger v0.2.0/go.mod h1:T9E3cAhj2VqvPOtCYAvby9aBXkZmbF5NWuPV8+WeEW8=
github.com/Azure/go-autorest/tracing v0.6.0/go.mod h1:+vhtPC754Xsa23ID7GlGsrdKBpUA79WCAKPPZVC2DeU=
github.com/BurntSushi/toml v0.3.1 h1:WXkYYl6Yr3qBf1K79EBnL4mak0OimBfB0XUf9Vl28OQ=
github.com/BurntSushi/toml v0.3.1/go.mod h1:xHWCNGjB5oqiDr8zfno3MHue2Ht5sIBksp03qcyfWMU=
github.com/BurntSushi/xgb v0.0.0-20160522181843-27f122750802/go.mod h1:IVnqGOEym/WlBOVXweHU+Q+/VP0lqqI8lqeDx9IjBqo=
github.com/GoogleCloudPlatform/cloudsql-proxy v1.19.1/go.mod h1:+yYmuKqcBVkgRePGpUhTA9OEg0XsnFE96eZ6nJ2yCQM=
@ -115,6 +116,8 @@ github.com/dgrijalva/jwt-go v3.2.0+incompatible/go.mod h1:E3ru+11k8xSBh+hMPgOLZm
github.com/dgryski/go-sip13 v0.0.0-20181026042036-e10d5fee7954/go.mod h1:vAd38F8PWV+bWy6jNmig1y/TA+kYO4g3RSRF0IAv0no=
github.com/dimchansky/utfbom v1.1.0/go.mod h1:rO41eb7gLfo8SF1jd9F8HplJm1Fewwi4mQvIirEdv+8=
github.com/dimchansky/utfbom v1.1.1/go.mod h1:SxdoEBH5qIqFocHMyGOXVAybYJdr71b1Q/j0mACtrfE=
github.com/dustinkirkland/golang-petname v0.0.0-20191129215211-8e5a1ed0cff0 h1:90Ly+6UfUypEF6vvvW5rQIv9opIL8CbmW9FT20LDQoY=
github.com/dustinkirkland/golang-petname v0.0.0-20191129215211-8e5a1ed0cff0/go.mod h1:V+Qd57rJe8gd4eiGzZyg4h54VLHmYVVw54iMnlAMrF8=
github.com/envoyproxy/go-control-plane v0.9.0/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
github.com/envoyproxy/go-control-plane v0.9.1-0.20191026205805-5f8ba28d4473/go.mod h1:YTl/9mNaCwkRvm6d1a2C3ymFceY/DCBVvsKhRF0iEA4=
github.com/envoyproxy/go-control-plane v0.9.4/go.mod h1:6rpuAdCZL397s3pYoYcLgu1mIlRU8Am5FuJP05cCM98=
@ -220,6 +223,7 @@ github.com/google/wire v0.4.0/go.mod h1:ngWDr9Qvq3yZA10YrxfyGELY/AFWGVpy9c1LTRi1
github.com/googleapis/gax-go/v2 v2.0.4/go.mod h1:0Wqv26UfaUD9n4G6kQubkQ+KchISgw+vpHVxEJEs9eg=
github.com/googleapis/gax-go/v2 v2.0.5 h1:sjZBwGj9Jlw33ImPtvFviGYvseOtDM7hkSKB7+Tv3SM=
github.com/googleapis/gax-go/v2 v2.0.5/go.mod h1:DWXyrwAJ9X0FpwwEdw+IPEYBICEFu5mhpdKc/us6bOk=
github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1 h1:EGx4pi6eqNxGaHF6qqu48+N2wcFQ5qg5FXgOdqsJ5d8=
github.com/gopherjs/gopherjs v0.0.0-20181017120253-0766667cb4d1/go.mod h1:wJfORRmW1u3UXTncJ5qlYoELFm8eSnnEO6hX4iZ3EWY=
github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
@ -266,6 +270,7 @@ github.com/json-iterator/go v1.1.9/go.mod h1:KdQUCv79m/52Kvf8AW2vK1V8akMuk1QjK/u
github.com/jstemmer/go-junit-report v0.0.0-20190106144839-af01ea7f8024/go.mod h1:6v2b51hI/fHJwM22ozAgKL4VKDeJcHhJFhtBdhmNjmU=
github.com/jstemmer/go-junit-report v0.9.1 h1:6QPYqodiu3GuPL+7mfx+NwDdp2eTkp9IfEUpgAwUN0o=
github.com/jstemmer/go-junit-report v0.9.1/go.mod h1:Brl9GWCQeLvo8nXZwPNNblvFj/XSXhF0NWZEnDohbsk=
github.com/jtolds/gls v4.20.0+incompatible h1:xdiiI2gbIgH/gLH7ADydsJ1uDOEzR8yvV7C0MuV77Wo=
github.com/jtolds/gls v4.20.0+incompatible/go.mod h1:QJZ7F/aHp+rZTRtaJ1ow/lLfFfVYBRgL+9YlvaHOwJU=
github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7VTCxuUUipMqKk8s4w=
github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
@ -276,6 +281,7 @@ github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxv
github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORNo=
github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
github.com/leodido/go-urn v1.2.0/go.mod h1:+8+nEpDfqqsY+g338gtMEUOtuK+4dEMhiQEgxpxOKII=
github.com/lib/pq v1.9.0/go.mod h1:AlVN5x4E4T544tWzH6hKfbfQvm3HdbOxrmggDNAPY9o=
@ -304,6 +310,7 @@ github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJ
github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
github.com/modern-go/reflect2 v1.0.1/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=
github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e/go.mod h1:zD1mROLANZcx1PVRCS0qkT7pwLkGfwJo4zjcN/Tysno=
github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
github.com/pascaldekloe/goe v0.0.0-20180627143212-57f6aae5913c/go.mod h1:lzWF7FIEvWOWxwDKqyGYQf6ZUaNfKdP144TG7ZOy1lc=
@ -332,7 +339,9 @@ github.com/ryanuber/columnize v0.0.0-20160712163229-9b3edd62028f/go.mod h1:sm1tb
github.com/sean-/seed v0.0.0-20170313163322-e2103e2c3529/go.mod h1:DxrIzT+xaE7yg65j358z/aeFdxmN0P9QXhEzd20vsDc=
github.com/shurcooL/sanitized_anchor_name v1.0.0/go.mod h1:1NzhyTcUVG4SuEtjjoZeVRXNmyL/1OwPU0+IJeTBvfc=
github.com/sirupsen/logrus v1.2.0/go.mod h1:LxeOpSwHxABJmUn/MG1IvRgCAasNZTLOkJPxbbu5VWo=
github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d h1:zE9ykElWQ6/NYmHa3jpm/yHnI4xSofP+UP6SpjHcSeM=
github.com/smartystreets/assertions v0.0.0-20180927180507-b2de0cb4f26d/go.mod h1:OnSkiWE9lh6wB0YB77sQom3nweQdgAjqCqsofrRNTgc=
github.com/smartystreets/goconvey v1.6.4 h1:fv0U8FUIMPNf1L9lnHLvLhgicrIVChEkdzIKYqbNC9s=
github.com/smartystreets/goconvey v1.6.4/go.mod h1:syvi0/a8iFYH4r/RixwvyeAJjdLS9QV7WQ/tjFTllLA=
github.com/soheilhy/cmux v0.1.4/go.mod h1:IM3LyeVVIOuxMH7sFAkER9+bJ4dT7Ms6E4xg4kGIyLM=
github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
@ -347,7 +356,6 @@ github.com/spf13/jwalterweatherman v1.0.0/go.mod h1:cQK4TGJAtQXfYWX+Ddv3mKDzgVb6
github.com/spf13/pflag v1.0.3/go.mod h1:DYY7MBk1bdzusC3SYhjObp+wFpr4gzcvqqNjLnInEg4=
github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
github.com/spf13/viper v1.7.0 h1:xVKxvI7ouOI5I+U9s2eeiUfMaWBVoXA3AWskkrqK0VM=
github.com/spf13/viper v1.7.0/go.mod h1:8WkrPz2fc9jxqZNCJI/76HCieCp4Q8HaLFoCha5qpdg=
github.com/spf13/viper v1.7.1 h1:pM5oEahlgWv/WnHXpgbKz7iLIxRf65tye2Ci+XFK5sk=
github.com/spf13/viper v1.7.1/go.mod h1:8WkrPz2fc9jxqZNCJI/76HCieCp4Q8HaLFoCha5qpdg=
@ -358,6 +366,7 @@ github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXf
github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
github.com/stretchr/testify v1.6.1 h1:hDPOHmpOpP40lSULcqw7IrRb/u7w6RpDC9399XyoNd0=
github.com/stretchr/testify v1.6.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/h/Wwjteg=
github.com/subosito/gotenv v1.2.0 h1:Slr1R9HxAlEKefgq5jn9U+DnETlIUa6HfgEzj0g5d7s=
github.com/subosito/gotenv v1.2.0/go.mod h1:N0PQaV/YGNqwC0u51sEeR/aUtSLEXKX9iv69rRypqCw=
@ -699,6 +708,7 @@ google.golang.org/protobuf v1.25.0/go.mod h1:9JNX74DMeImyA3h4bdi1ymwjUzf21/xIlba
gopkg.in/alecthomas/kingpin.v2 v2.2.6/go.mod h1:FMv+mEhP44yOT+4EoQTLFTRgOQ1FBLkstjWtayDeSgw=
gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f h1:BLraFXnmrev5lT+xlilqcH8XK9/i0At2xKjWk4p6zsU=
gopkg.in/check.v1 v1.0.0-20200227125254-8fa46927fb4f/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
gopkg.in/errgo.v2 v2.1.0/go.mod h1:hNsd1EY+bozCKY1Ytp96fpM3vjJbqLJn88ws8XvfDNI=
gopkg.in/ini.v1 v1.51.0 h1:AQvPpx3LzTDM0AjnIRlVFwFFGC+npRopjZxLJj6gdno=
@ -711,6 +721,7 @@ gopkg.in/yaml.v2 v2.2.4/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
gopkg.in/yaml.v2 v2.2.8/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
gopkg.in/yaml.v2 v2.4.0 h1:D8xgwECY7CYvx+Y2n4sBz93Jn9JRvxdiyyo8CTfuKaY=
gopkg.in/yaml.v2 v2.4.0/go.mod h1:RDklbk79AGWmwhnvt/jBztapEOGDOx6ZbXqjP6csGnQ=
gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
honnef.co/go/tools v0.0.0-20190102054323-c2f93a96b099/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=
honnef.co/go/tools v0.0.0-20190106161140-3f1c8253044a/go.mod h1:rf3lG4BRIbNafJWhAfAdb/ePZxsR/4RtNHQocxwk9r4=