blob: 18ab428ce0e6c559859163ee6003ed682b01af57 [file] [log] [blame]
// Copyright 2013 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 or at
// https://developers.google.com/open-source/licenses/bsd.
// Redis keys and types:
//
// maxPackageId string: next id to assign
// ids hash maps import path to package id
// pkg:<id> hash
// terms: space separated search terms
// path: import path
// synopsis: synopsis
// gob: snappy compressed gob encoded doc.Package
// score: document search score
// etag:
// kind: p=package, c=command, d=directory with no go files
// index:<term> set: package ids for given search term
// index:import:<path> set: packages with import path
// index:project:<root> set: packages in project with root
// block set: packages to block
// popular zset: package id, score
// popular:0 string: scaled base time for popular scores
// nextCrawl zset: package id, Unix time for next crawl
// newCrawl set: new paths to crawl
// badCrawl set: paths that returned error when crawling.
// Package database manages storage for GoPkgDoc.
package database
import (
"bytes"
"encoding/gob"
"errors"
"flag"
"fmt"
"log"
"math"
"net/url"
"os"
"path"
"sort"
"strconv"
"strings"
"time"
"github.com/garyburd/redigo/redis"
"github.com/golang/gddo/doc"
"github.com/golang/gddo/gosrc"
"github.com/golang/snappy"
)
type Database struct {
Pool interface {
Get() redis.Conn
}
}
type Package struct {
Path string `json:"path"`
Synopsis string `json:"synopsis,omitempty"`
}
type byPath []Package
func (p byPath) Len() int { return len(p) }
func (p byPath) Less(i, j int) bool { return p[i].Path < p[j].Path }
func (p byPath) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
var (
redisServer = flag.String("db-server", "redis://127.0.0.1:6379", "URI of Redis server.")
redisIdleTimeout = flag.Duration("db-idle-timeout", 250*time.Second, "Close Redis connections after remaining idle for this duration.")
redisLog = flag.Bool("db-log", false, "Log database commands")
)
func dialDb() (c redis.Conn, err error) {
u, err := url.Parse(*redisServer)
if err != nil {
return nil, err
}
defer func() {
if err != nil && c != nil {
c.Close()
}
}()
c, err = redis.Dial("tcp", u.Host)
if err != nil {
return
}
if *redisLog {
l := log.New(os.Stderr, "", log.LstdFlags)
c = redis.NewLoggingConn(c, l, "")
}
if u.User != nil {
if pw, ok := u.User.Password(); ok {
if _, err = c.Do("AUTH", pw); err != nil {
return
}
}
}
return
}
// New creates a database configured from command line flags.
func New() (*Database, error) {
pool := &redis.Pool{
Dial: dialDb,
MaxIdle: 10,
IdleTimeout: *redisIdleTimeout,
}
if c := pool.Get(); c.Err() != nil {
return nil, c.Err()
} else {
c.Close()
}
return &Database{Pool: pool}, nil
}
// Exists returns true if package with import path exists in the database.
func (db *Database) Exists(path string) (bool, error) {
c := db.Pool.Get()
defer c.Close()
return redis.Bool(c.Do("HEXISTS", "ids", path))
}
var putScript = redis.NewScript(0, `
local path = ARGV[1]
local synopsis = ARGV[2]
local score = ARGV[3]
local gob = ARGV[4]
local terms = ARGV[5]
local etag = ARGV[6]
local kind = ARGV[7]
local nextCrawl = ARGV[8]
local id = redis.call('HGET', 'ids', path)
if not id then
id = redis.call('INCR', 'maxPackageId')
redis.call('HSET', 'ids', path, id)
end
if etag ~= '' and etag == redis.call('HGET', 'pkg:' .. id, 'clone') then
terms = ''
score = 0
end
local update = {}
for term in string.gmatch(redis.call('HGET', 'pkg:' .. id, 'terms') or '', '([^ ]+)') do
update[term] = 1
end
for term in string.gmatch(terms, '([^ ]+)') do
update[term] = (update[term] or 0) + 2
end
for term, x in pairs(update) do
if x == 1 then
redis.call('SREM', 'index:' .. term, id)
elseif x == 2 then
redis.call('SADD', 'index:' .. term, id)
end
end
redis.call('SREM', 'badCrawl', path)
redis.call('SREM', 'newCrawl', path)
if nextCrawl ~= '0' then
redis.call('ZADD', 'nextCrawl', nextCrawl, id)
redis.call('HSET', 'pkg:' .. id, 'crawl', nextCrawl)
end
return redis.call('HMSET', 'pkg:' .. id, 'path', path, 'synopsis', synopsis, 'score', score, 'gob', gob, 'terms', terms, 'etag', etag, 'kind', kind)
`)
var addCrawlScript = redis.NewScript(0, `
for i=1,#ARGV do
local pkg = ARGV[i]
if redis.call('HEXISTS', 'ids', pkg) == 0 and redis.call('SISMEMBER', 'badCrawl', pkg) == 0 then
redis.call('SADD', 'newCrawl', pkg)
end
end
`)
func (db *Database) AddNewCrawl(importPath string) error {
if !gosrc.IsValidRemotePath(importPath) {
return errors.New("bad path")
}
c := db.Pool.Get()
defer c.Close()
_, err := addCrawlScript.Do(c, importPath)
return err
}
// Put adds the package documentation to the database.
func (db *Database) Put(pdoc *doc.Package, nextCrawl time.Time, hide bool) error {
c := db.Pool.Get()
defer c.Close()
score := 0.0
if !hide {
score = documentScore(pdoc)
}
terms := documentTerms(pdoc, score)
var gobBuf bytes.Buffer
if err := gob.NewEncoder(&gobBuf).Encode(pdoc); err != nil {
return err
}
gobBytes := snappy.Encode(nil, gobBuf.Bytes())
// Truncate large documents.
if len(gobBytes) > 400000 {
pdocNew := *pdoc
pdoc = &pdocNew
pdoc.Truncated = true
pdoc.Vars = nil
pdoc.Funcs = nil
pdoc.Types = nil
pdoc.Consts = nil
pdoc.Examples = nil
gobBuf.Reset()
if err := gob.NewEncoder(&gobBuf).Encode(pdoc); err != nil {
return err
}
gobBytes = snappy.Encode(nil, gobBuf.Bytes())
}
kind := "p"
switch {
case pdoc.Name == "":
kind = "d"
case pdoc.IsCmd:
kind = "c"
}
t := int64(0)
if !nextCrawl.IsZero() {
t = nextCrawl.Unix()
}
_, err := putScript.Do(c, pdoc.ImportPath, pdoc.Synopsis, score, gobBytes, strings.Join(terms, " "), pdoc.Etag, kind, t)
if err != nil {
return err
}
if nextCrawl.IsZero() {
// Skip crawling related packages if this is not a full save.
return nil
}
paths := make(map[string]bool)
for _, p := range pdoc.Imports {
if gosrc.IsValidRemotePath(p) {
paths[p] = true
}
}
for _, p := range pdoc.TestImports {
if gosrc.IsValidRemotePath(p) {
paths[p] = true
}
}
for _, p := range pdoc.XTestImports {
if gosrc.IsValidRemotePath(p) {
paths[p] = true
}
}
if pdoc.ImportPath != pdoc.ProjectRoot && pdoc.ProjectRoot != "" {
paths[pdoc.ProjectRoot] = true
}
for _, p := range pdoc.Subdirectories {
paths[pdoc.ImportPath+"/"+p] = true
}
args := make([]interface{}, 0, len(paths))
for p := range paths {
args = append(args, p)
}
_, err = addCrawlScript.Do(c, args...)
return err
}
var setNextCrawlEtagScript = redis.NewScript(0, `
local root = ARGV[1]
local etag = ARGV[2]
local nextCrawl = ARGV[3]
local pkgs = redis.call('SORT', 'index:project:' .. root, 'GET', '#', 'GET', 'pkg:*->etag')
for i=1,#pkgs,2 do
if pkgs[i+1] == etag then
redis.call('ZADD', 'nextCrawl', nextCrawl, pkgs[i])
redis.call('HSET', 'pkg:' .. pkgs[i], 'crawl', nextCrawl)
end
end
`)
// SetNextCrawlEtag sets the next crawl time for all packages in the project with the given etag.
func (db *Database) SetNextCrawlEtag(projectRoot string, etag string, t time.Time) error {
c := db.Pool.Get()
defer c.Close()
_, err := setNextCrawlEtagScript.Do(c, normalizeProjectRoot(projectRoot), etag, t.Unix())
return err
}
// bumpCrawlScript sets the crawl time to now. To avoid continuously crawling
// frequently updated repositories, the crawl is scheduled in the future.
var bumpCrawlScript = redis.NewScript(0, `
local root = ARGV[1]
local now = tonumber(ARGV[2])
local nextCrawl = now + 7200
local pkgs = redis.call('SORT', 'index:project:' .. root, 'GET', '#')
for i=1,#pkgs do
local v = redis.call('HMGET', 'pkg:' .. pkgs[i], 'crawl', 'kind')
local t = tonumber(v[1] or 0)
if t == 0 or now < t then
redis.call('HSET', 'pkg:' .. pkgs[i], 'crawl', now)
end
local nextCrawl = now + 86400
if v[2] == 'p' then
nextCrawl = now + 7200
end
t = tonumber(redis.call('ZSCORE', 'nextCrawl', pkgs[i]) or 0)
if t == 0 or nextCrawl < t then
redis.call('ZADD', 'nextCrawl', nextCrawl, pkgs[i])
end
end
`)
func (db *Database) BumpCrawl(projectRoot string) error {
c := db.Pool.Get()
defer c.Close()
_, err := bumpCrawlScript.Do(c, normalizeProjectRoot(projectRoot), time.Now().Unix())
return err
}
// getDocScript gets the package documentation and update time for the
// specified path. If path is "-", then the oldest document is returned.
var getDocScript = redis.NewScript(0, `
local path = ARGV[1]
local id
if path == '-' then
local r = redis.call('ZRANGE', 'nextCrawl', 0, 0)
if not r or #r == 0 then
return false
end
id = r[1]
else
id = redis.call('HGET', 'ids', path)
if not id then
return false
end
end
local gob = redis.call('HGET', 'pkg:' .. id, 'gob')
if not gob then
return false
end
local nextCrawl = redis.call('HGET', 'pkg:' .. id, 'crawl')
if not nextCrawl then
nextCrawl = redis.call('ZSCORE', 'nextCrawl', id)
if not nextCrawl then
nextCrawl = 0
end
end
return {gob, nextCrawl}
`)
func (db *Database) getDoc(c redis.Conn, path string) (*doc.Package, time.Time, error) {
r, err := redis.Values(getDocScript.Do(c, path))
if err == redis.ErrNil {
return nil, time.Time{}, nil
} else if err != nil {
return nil, time.Time{}, err
}
var p []byte
var t int64
if _, err := redis.Scan(r, &p, &t); err != nil {
return nil, time.Time{}, err
}
p, err = snappy.Decode(nil, p)
if err != nil {
return nil, time.Time{}, err
}
var pdoc doc.Package
if err := gob.NewDecoder(bytes.NewReader(p)).Decode(&pdoc); err != nil {
return nil, time.Time{}, err
}
nextCrawl := pdoc.Updated
if t != 0 {
nextCrawl = time.Unix(t, 0).UTC()
}
return &pdoc, nextCrawl, err
}
var getSubdirsScript = redis.NewScript(0, `
local reply
for i = 1,#ARGV do
reply = redis.call('SORT', 'index:project:' .. ARGV[i], 'ALPHA', 'BY', 'pkg:*->path', 'GET', 'pkg:*->path', 'GET', 'pkg:*->synopsis', 'GET', 'pkg:*->kind')
if #reply > 0 then
break
end
end
return reply
`)
func (db *Database) getSubdirs(c redis.Conn, path string, pdoc *doc.Package) ([]Package, error) {
var reply interface{}
var err error
switch {
case isStandardPackage(path):
reply, err = getSubdirsScript.Do(c, "go")
case pdoc != nil:
reply, err = getSubdirsScript.Do(c, pdoc.ProjectRoot)
default:
var roots []interface{}
projectRoot := path
for i := 0; i < 5; i++ {
roots = append(roots, projectRoot)
if j := strings.LastIndex(projectRoot, "/"); j < 0 {
break
} else {
projectRoot = projectRoot[:j]
}
}
reply, err = getSubdirsScript.Do(c, roots...)
}
values, err := redis.Values(reply, err)
if err != nil {
return nil, err
}
var subdirs []Package
prefix := path + "/"
for len(values) > 0 {
var pkg Package
var kind string
values, err = redis.Scan(values, &pkg.Path, &pkg.Synopsis, &kind)
if err != nil {
return nil, err
}
if (kind == "p" || kind == "c") && strings.HasPrefix(pkg.Path, prefix) {
subdirs = append(subdirs, pkg)
}
}
return subdirs, err
}
// Get gets the package documenation and sub-directories for the the given
// import path.
func (db *Database) Get(path string) (*doc.Package, []Package, time.Time, error) {
c := db.Pool.Get()
defer c.Close()
pdoc, nextCrawl, err := db.getDoc(c, path)
if err != nil {
return nil, nil, time.Time{}, err
}
if pdoc != nil {
// fixup for speclal "-" path.
path = pdoc.ImportPath
}
subdirs, err := db.getSubdirs(c, path, pdoc)
if err != nil {
return nil, nil, time.Time{}, err
}
return pdoc, subdirs, nextCrawl, nil
}
func (db *Database) GetDoc(path string) (*doc.Package, time.Time, error) {
c := db.Pool.Get()
defer c.Close()
return db.getDoc(c, path)
}
var deleteScript = redis.NewScript(0, `
local path = ARGV[1]
local id = redis.call('HGET', 'ids', path)
if not id then
return false
end
for term in string.gmatch(redis.call('HGET', 'pkg:' .. id, 'terms') or '', '([^ ]+)') do
redis.call('SREM', 'index:' .. term, id)
end
redis.call('ZREM', 'nextCrawl', id)
redis.call('SREM', 'newCrawl', path)
redis.call('ZREM', 'popular', id)
redis.call('DEL', 'pkg:' .. id)
return redis.call('HDEL', 'ids', path)
`)
// Delete deletes the documenation for the given import path.
func (db *Database) Delete(path string) error {
c := db.Pool.Get()
defer c.Close()
_, err := deleteScript.Do(c, path)
return err
}
func packages(reply interface{}, all bool) ([]Package, error) {
values, err := redis.Values(reply, nil)
if err != nil {
return nil, err
}
result := make([]Package, 0, len(values)/3)
for len(values) > 0 {
var pkg Package
var kind string
values, err = redis.Scan(values, &pkg.Path, &pkg.Synopsis, &kind)
if err != nil {
return nil, err
}
if !all && kind == "d" {
continue
}
if pkg.Path == "C" {
pkg.Synopsis = "Package C is a \"pseudo-package\" used to access the C namespace from a cgo source file."
}
result = append(result, pkg)
}
return result, nil
}
func (db *Database) getPackages(key string, all bool) ([]Package, error) {
c := db.Pool.Get()
defer c.Close()
reply, err := c.Do("SORT", key, "ALPHA", "BY", "pkg:*->path", "GET", "pkg:*->path", "GET", "pkg:*->synopsis", "GET", "pkg:*->kind")
if err != nil {
return nil, err
}
return packages(reply, all)
}
func (db *Database) GoIndex() ([]Package, error) {
return db.getPackages("index:project:go", false)
}
func (db *Database) GoSubrepoIndex() ([]Package, error) {
return db.getPackages("index:project:subrepo", false)
}
func (db *Database) Index() ([]Package, error) {
return db.getPackages("index:all:", false)
}
func (db *Database) Project(projectRoot string) ([]Package, error) {
return db.getPackages("index:project:"+normalizeProjectRoot(projectRoot), true)
}
func (db *Database) AllPackages() ([]Package, error) {
c := db.Pool.Get()
defer c.Close()
values, err := redis.Values(c.Do("SORT", "nextCrawl", "DESC", "BY", "pkg:*->score", "GET", "pkg:*->path", "GET", "pkg:*->kind"))
if err != nil {
return nil, err
}
result := make([]Package, 0, len(values)/2)
for len(values) > 0 {
var pkg Package
var kind string
values, err = redis.Scan(values, &pkg.Path, &kind)
if err != nil {
return nil, err
}
if kind == "d" {
continue
}
result = append(result, pkg)
}
return result, nil
}
var packagesScript = redis.NewScript(0, `
local result = {}
for i = 1,#ARGV do
local path = ARGV[i]
local synopsis = ''
local kind = 'u'
local id = redis.call('HGET', 'ids', path)
if id then
synopsis = redis.call('HGET', 'pkg:' .. id, 'synopsis')
kind = redis.call('HGET', 'pkg:' .. id, 'kind')
end
result[#result+1] = path
result[#result+1] = synopsis
result[#result+1] = kind
end
return result
`)
func (db *Database) Packages(paths []string) ([]Package, error) {
var args []interface{}
for _, p := range paths {
args = append(args, p)
}
c := db.Pool.Get()
defer c.Close()
reply, err := packagesScript.Do(c, args...)
if err != nil {
return nil, err
}
pkgs, err := packages(reply, false)
sort.Sort(byPath(pkgs))
return pkgs, err
}
func (db *Database) ImporterCount(path string) (int, error) {
c := db.Pool.Get()
defer c.Close()
return redis.Int(c.Do("SCARD", "index:import:"+path))
}
func (db *Database) Importers(path string) ([]Package, error) {
return db.getPackages("index:import:"+path, false)
}
func (db *Database) Block(root string) error {
c := db.Pool.Get()
defer c.Close()
if _, err := c.Do("SADD", "block", root); err != nil {
return err
}
keys, err := redis.Strings(c.Do("HKEYS", "ids"))
if err != nil {
return err
}
for _, key := range keys {
if key == root || strings.HasPrefix(key, root) && key[len(root)] == '/' {
if _, err := deleteScript.Do(c, key); err != nil {
return err
}
}
}
return nil
}
var isBlockedScript = redis.NewScript(0, `
local path = ''
for s in string.gmatch(ARGV[1], '[^/]+') do
path = path .. s
if redis.call('SISMEMBER', 'block', path) == 1 then
return 1
end
path = path .. '/'
end
return 0
`)
func (db *Database) IsBlocked(path string) (bool, error) {
c := db.Pool.Get()
defer c.Close()
return redis.Bool(isBlockedScript.Do(c, path))
}
type queryResult struct {
Path string
Synopsis string
Score float64
}
type byScore []*queryResult
func (p byScore) Len() int { return len(p) }
func (p byScore) Less(i, j int) bool { return p[j].Score < p[i].Score }
func (p byScore) Swap(i, j int) { p[i], p[j] = p[j], p[i] }
func (db *Database) Query(q string) ([]Package, error) {
terms := parseQuery(q)
if len(terms) == 0 {
return nil, nil
}
c := db.Pool.Get()
defer c.Close()
n, err := redis.Int(c.Do("INCR", "maxQueryId"))
if err != nil {
return nil, err
}
id := "tmp:query-" + strconv.Itoa(n)
args := []interface{}{id}
for _, term := range terms {
args = append(args, "index:"+term)
}
c.Send("SINTERSTORE", args...)
c.Send("SORT", id, "DESC", "BY", "nosort", "GET", "pkg:*->path", "GET", "pkg:*->synopsis", "GET", "pkg:*->score")
c.Send("DEL", id)
c.Flush()
c.Receive() // SINTERSTORE
values, err := redis.Values(c.Receive()) // SORT
if err != nil {
return nil, err
}
c.Receive() // DEL
var queryResults []*queryResult
if err := redis.ScanSlice(values, &queryResults, "Path", "Synopsis", "Score"); err != nil {
return nil, err
}
for _, qr := range queryResults {
c.Send("SCARD", "index:import:"+qr.Path)
}
c.Flush()
for _, qr := range queryResults {
importCount, err := redis.Int(c.Receive())
if err != nil {
return nil, err
}
qr.Score *= math.Log(float64(10 + importCount))
if isStandardPackage(qr.Path) {
if strings.HasSuffix(qr.Path, q) {
// Big bump for exact match on standard package name.
qr.Score *= 10000
} else {
qr.Score *= 1.2
}
}
if q == path.Base(qr.Path) {
qr.Score *= 1.1
}
}
sort.Sort(byScore(queryResults))
pkgs := make([]Package, len(queryResults))
for i, qr := range queryResults {
pkgs[i].Path = qr.Path
pkgs[i].Synopsis = qr.Synopsis
}
return pkgs, nil
}
type PackageInfo struct {
PDoc *doc.Package
Score float64
Kind string
Size int
}
// Do executes function f for each document in the database.
func (db *Database) Do(f func(*PackageInfo) error) error {
c := db.Pool.Get()
defer c.Close()
cursor := 0
c.Send("SCAN", cursor, "MATCH", "pkg:*")
c.Flush()
for {
// Recieve previous SCAN.
values, err := redis.Values(c.Receive())
if err != nil {
return err
}
var keys [][]byte
if _, err := redis.Scan(values, &cursor, &keys); err != nil {
return err
}
if cursor == 0 {
break
}
for _, key := range keys {
c.Send("HMGET", key, "gob", "score", "kind", "path", "terms", "synopis")
}
c.Send("SCAN", cursor, "MATCH", "pkg:*")
c.Flush()
for _ = range keys {
values, err := redis.Values(c.Receive())
if err != nil {
return err
}
var (
pi PackageInfo
p []byte
path string
terms string
synopsis string
)
if _, err := redis.Scan(values, &p, &pi.Score, &pi.Kind, &path, &terms, &synopsis); err != nil {
return err
}
if p == nil {
continue
}
pi.Size = len(path) + len(p) + len(terms) + len(synopsis)
p, err = snappy.Decode(nil, p)
if err != nil {
return fmt.Errorf("snappy decoding %s: %v", path, err)
}
if err := gob.NewDecoder(bytes.NewReader(p)).Decode(&pi.PDoc); err != nil {
return fmt.Errorf("gob decoding %s: %v", path, err)
}
if err := f(&pi); err != nil {
return fmt.Errorf("func %s: %v", path, err)
}
}
}
return nil
}
var importGraphScript = redis.NewScript(0, `
local path = ARGV[1]
local id = redis.call('HGET', 'ids', path)
if not id then
return false
end
return redis.call('HMGET', 'pkg:' .. id, 'synopsis', 'terms')
`)
// DepLevel specifies the level of depdenencies to show in an import graph.
type DepLevel int
const (
ShowAllDeps DepLevel = iota // show all dependencies
HideStandardDeps // don't show dependencies of standard libraries
HideStandardAll // don't show standard libraries at all
)
func (db *Database) ImportGraph(pdoc *doc.Package, level DepLevel) ([]Package, [][2]int, error) {
// This breadth-first traversal of the package's dependencies uses the
// Redis pipeline as queue. Links to packages with invalid import paths are
// only included for the root package.
c := db.Pool.Get()
defer c.Close()
if err := importGraphScript.Load(c); err != nil {
return nil, nil, err
}
nodes := []Package{{Path: pdoc.ImportPath, Synopsis: pdoc.Synopsis}}
edges := [][2]int{}
index := map[string]int{pdoc.ImportPath: 0}
for _, path := range pdoc.Imports {
if level >= HideStandardAll && isStandardPackage(path) {
continue
}
j := len(nodes)
index[path] = j
edges = append(edges, [2]int{0, j})
nodes = append(nodes, Package{Path: path})
importGraphScript.Send(c, path)
}
for i := 1; i < len(nodes); i++ {
c.Flush()
r, err := redis.Values(c.Receive())
if err == redis.ErrNil {
continue
} else if err != nil {
return nil, nil, err
}
var synopsis, terms string
if _, err := redis.Scan(r, &synopsis, &terms); err != nil {
return nil, nil, err
}
nodes[i].Synopsis = synopsis
for _, term := range strings.Fields(terms) {
if strings.HasPrefix(term, "import:") {
path := term[len("import:"):]
if level >= HideStandardDeps && isStandardPackage(path) {
continue
}
j, ok := index[path]
if !ok {
j = len(nodes)
index[path] = j
nodes = append(nodes, Package{Path: path})
importGraphScript.Send(c, path)
}
edges = append(edges, [2]int{i, j})
}
}
}
return nodes, edges, nil
}
func (db *Database) PutGob(key string, value interface{}) error {
var buf bytes.Buffer
if err := gob.NewEncoder(&buf).Encode(value); err != nil {
return err
}
c := db.Pool.Get()
defer c.Close()
_, err := c.Do("SET", "gob:"+key, buf.Bytes())
return err
}
func (db *Database) GetGob(key string, value interface{}) error {
c := db.Pool.Get()
defer c.Close()
p, err := redis.Bytes(c.Do("GET", "gob:"+key))
if err == redis.ErrNil {
return nil
} else if err != nil {
return err
}
return gob.NewDecoder(bytes.NewReader(p)).Decode(value)
}
var incrementPopularScoreScript = redis.NewScript(0, `
local path = ARGV[1]
local n = ARGV[2]
local t = ARGV[3]
local id = redis.call('HGET', 'ids', path)
if not id then
return
end
local t0 = redis.call('GET', 'popular:0') or '0'
local f = math.exp(tonumber(t) - tonumber(t0))
redis.call('ZINCRBY', 'popular', tonumber(n) * f, id)
if f > 10 then
redis.call('SET', 'popular:0', t)
redis.call('ZUNIONSTORE', 'popular', 1, 'popular', 'WEIGHTS', 1.0 / f)
redis.call('ZREMRANGEBYSCORE', 'popular', '-inf', 0.05)
end
`)
const popularHalfLife = time.Hour * 24 * 7
func (db *Database) incrementPopularScoreInternal(path string, delta float64, t time.Time) error {
// nt = n0 * math.Exp(-lambda * t)
// lambda = math.Ln2 / thalf
c := db.Pool.Get()
defer c.Close()
const lambda = math.Ln2 / float64(popularHalfLife)
scaledTime := lambda * float64(t.Sub(time.Unix(1257894000, 0)))
_, err := incrementPopularScoreScript.Do(c, path, delta, scaledTime)
return err
}
func (db *Database) IncrementPopularScore(path string) error {
return db.incrementPopularScoreInternal(path, 1, time.Now())
}
var popularScript = redis.NewScript(0, `
local stop = ARGV[1]
local ids = redis.call('ZREVRANGE', 'popular', '0', stop)
local result = {}
for i=1,#ids do
local values = redis.call('HMGET', 'pkg:' .. ids[i], 'path', 'synopsis', 'kind')
result[#result+1] = values[1]
result[#result+1] = values[2]
result[#result+1] = values[3]
end
return result
`)
func (db *Database) Popular(count int) ([]Package, error) {
c := db.Pool.Get()
defer c.Close()
reply, err := popularScript.Do(c, count-1)
if err != nil {
return nil, err
}
pkgs, err := packages(reply, false)
return pkgs, err
}
var popularWithScoreScript = redis.NewScript(0, `
local ids = redis.call('ZREVRANGE', 'popular', '0', -1, 'WITHSCORES')
local result = {}
for i=1,#ids,2 do
result[#result+1] = redis.call('HGET', 'pkg:' .. ids[i], 'path')
result[#result+1] = ids[i+1]
result[#result+1] = 'p'
end
return result
`)
func (db *Database) PopularWithScores() ([]Package, error) {
c := db.Pool.Get()
defer c.Close()
reply, err := popularWithScoreScript.Do(c)
if err != nil {
return nil, err
}
pkgs, err := packages(reply, false)
return pkgs, err
}
func (db *Database) PopNewCrawl() (string, bool, error) {
c := db.Pool.Get()
defer c.Close()
var subdirs []Package
path, err := redis.String(c.Do("SPOP", "newCrawl"))
switch {
case err == redis.ErrNil:
err = nil
path = ""
case err == nil:
subdirs, err = db.getSubdirs(c, path, nil)
}
return path, len(subdirs) > 0, err
}
func (db *Database) AddBadCrawl(path string) error {
c := db.Pool.Get()
defer c.Close()
_, err := c.Do("SADD", "badCrawl", path)
return err
}
var incrementCounterScript = redis.NewScript(0, `
local key = 'counter:' .. ARGV[1]
local n = tonumber(ARGV[2])
local t = tonumber(ARGV[3])
local exp = tonumber(ARGV[4])
local counter = redis.call('GET', key)
if counter then
counter = cjson.decode(counter)
n = n + counter.n * math.exp(counter.t - t)
end
redis.call('SET', key, cjson.encode({n = n; t = t}))
redis.call('EXPIRE', key, exp)
return tostring(n)
`)
const counterHalflife = time.Hour
func (db *Database) incrementCounterInternal(key string, delta float64, t time.Time) (float64, error) {
// nt = n0 * math.Exp(-lambda * t)
// lambda = math.Ln2 / thalf
c := db.Pool.Get()
defer c.Close()
const lambda = math.Ln2 / float64(counterHalflife)
scaledTime := lambda * float64(t.Sub(time.Unix(1257894000, 0)))
return redis.Float64(incrementCounterScript.Do(c, key, delta, scaledTime, (4*counterHalflife)/time.Second))
}
func (db *Database) IncrementCounter(key string, delta float64) (float64, error) {
return db.incrementCounterInternal(key, delta, time.Now())
}