README
¶
go-ipfs-colog
colog is a concurrent log. In the JS version of Orbit it is currently called log, but in many contexts a log is a linear sequence of events. To avoid confusion, the Go version was named colog.
Installing
go get the package, including the deps for tests (-t):
go get -t github.com/keks/go-ipfs-colog
Test
Once successfully installed
go test github.com/keks/go-ipfs-colog
does the trick.
API documentation
You can find the API reference on godoc.
Documentation
¶
Index ¶
- type CoLog
- func (l *CoLog) Add(data interface{}) (*Entry, error)
- func (l *CoLog) Contains(h Hash) bool
- func (l *CoLog) FetchFromHead(head Hash) error
- func (l *CoLog) Get(h Hash) (*Entry, error)
- func (l *CoLog) Heads() []Hash
- func (l *CoLog) Items() []*Entry
- func (l *CoLog) Join(other *CoLog) error
- func (l *CoLog) Nexts(h Hash) HashSet
- func (l *CoLog) Prevs(h Hash) HashSet
- func (l *CoLog) Query(qry Query) Result
- func (l *CoLog) Unwatch(ch <-chan *Entry)
- func (l *CoLog) Watch() <-chan *Entry
- type Entry
- type Hash
- type HashSet
- func (s HashSet) Add(h Hash)
- func (s HashSet) Contains(h Hash) bool
- func (s HashSet) Copy() HashSet
- func (s HashSet) Count() int
- func (s HashSet) Drop(h Hash)
- func (s HashSet) MarshalJSON() ([]byte, error)
- func (s HashSet) Sorted() []Hash
- func (s HashSet) String() string
- func (s HashSet) UnmarshalJSON(in []byte) error
- type Index
- type Query
- type QueryBound
- type Result
Examples ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type CoLog ¶
type CoLog struct {
// contains filtered or unexported fields
}
CoLog is a concurrent log
Example (ConcurrentAccess) ¶
var wg sync.WaitGroup
l := New(ipfsdb)
n := 50
sum := 0
wg.Add(n)
for i := 0; i < n; i++ {
go func(j int) {
l.Add(j)
wg.Done()
}(i)
}
wg.Wait()
for _, e := range l.Items() {
var j int
err := json.Unmarshal(e.Value, &j)
if err != nil {
panic(err)
}
sum += j
}
// 1+2+3+4+...+n = n*(n+1)/2
// 0+1+2+3+...+n-1 = (n-1)*n/2
// = n*(n-1)/2
if sum != n*(n-1)/2 {
panic("wrong sum")
}
fmt.Println("ok")
Output: ok
func (*CoLog) Add ¶
Add adds data to the colog and returns the resulting entry
Example (One) ¶
var log1 = New(ipfsdb)
one, err := log1.Add(value1)
if err != nil {
panic(err)
}
fmt.Println(one.Hash)
fmt.Println(one.GetString())
fmt.Println(one.Prev)
Output: QmbiruS6UMT6gT3JBHtZNWKitEssyUQzYu8k4gGd6rhzNc Hello1 { null }
Example (Three) ¶
var log1 = New(ipfsdb)
log1.Add(value1)
log1.Add(value2)
log1.Add(value3)
items := log1.Items()
fmt.Println(len(items))
fmt.Println(string(items[0].GetString()))
fmt.Println(string(items[1].GetString()))
fmt.Println(string(items[2].GetString()))
fmt.Println(items[0].Prev)
e1, err := log1.Get(items[1].Prev.Sorted()[0])
if err != nil {
panic(err)
}
fmt.Println(e1.Hash)
e2, err := log1.Get(items[2].Prev.Sorted()[0])
if err != nil {
panic(err)
}
fmt.Println(e2.Hash)
Output: 3 Hello1 Hello2 Hello3 { null } QmbiruS6UMT6gT3JBHtZNWKitEssyUQzYu8k4gGd6rhzNc QmdezppSoeGZmyYQZEuiUTU4cxTqyVfiwBct7D5iosY6zN
Example (Two) ¶
var log1 = New(ipfsdb)
log1.Add(value1)
log1.Add(value2)
items := log1.Items()
fmt.Println(len(items))
fmt.Println(items[1].Hash)
fmt.Println(string(items[1].GetString()))
e, err := log1.Get(items[1].Prev.Sorted()[0])
if err != nil {
panic(err)
}
fmt.Println(e.Hash)
Output: 2 QmdezppSoeGZmyYQZEuiUTU4cxTqyVfiwBct7D5iosY6zN Hello2 QmbiruS6UMT6gT3JBHtZNWKitEssyUQzYu8k4gGd6rhzNc
func (*CoLog) FetchFromHead ¶
FetchFromHead takes a Hash `head' and recursively adds the entries behind the head
func (*CoLog) Items ¶
Items returns the Entries in canonical order
Example (Ordering) ¶
package main
import (
"fmt"
)
func checkadd(e *Entry, err error) *Entry {
check(err)
return e
}
func check(err error) {
if err != nil {
panic(err)
}
}
func main() {
l1 := New(ipfsdb)
l2 := New(ipfsdb)
l3 := New(ipfsdb)
checkadd(l1.Add("init"))
check(l2.Join(l1))
checkadd(l1.Add("simple fix"))
checkadd(l2.Add("fix simple bug"))
checkadd(l2.Add("oh i missed something"))
check(l1.Join(l2))
check(l2.Join(l1))
checkadd(l1.Add("bump version 0.2"))
check(l2.Join(l1))
checkadd(l2.Add("add feature"))
check(l1.Join(l2))
check(l3.Join(l2))
checkadd(l3.Add("add chinese translation"))
checkadd(l1.Add("add spanish translation"))
checkadd(l2.Add("add afrikaans translation"))
check(l1.Join(l3))
check(l3.Join(l1))
checkadd(l3.Add("fix i18n api"))
checkadd(l3.Add("add i18n feature"))
check(l1.Join(l2))
check(l1.Join(l3))
checkadd(l1.Add("version bump 0.3"))
for _, e := range l1.Items() {
fmt.Println(e.Hash, e.GetString(), e.Prev)
}
}
Output: QmT1yirz1BgNjWQJgefjz37UoZsc4aa5DDAdVFKcWQek3L init { null } QmYhvpaYk2MGwVGpHwM6gGS5GQu1esCBeueQBbpSXNPRRa fix simple bug { QmT1yirz1BgNjWQJgefjz37UoZsc4aa5DDAdVFKcWQek3L } QmcoQ6WHtjrFi6x1JB6VBLDEYzfgxaM9mYwXRJ953M2SJ8 oh i missed something { QmYhvpaYk2MGwVGpHwM6gGS5GQu1esCBeueQBbpSXNPRRa } QmYWcu4VkcQ7vvugSqJuwsVLwLijfhDj7UGyae2a8V1xY3 simple fix { QmT1yirz1BgNjWQJgefjz37UoZsc4aa5DDAdVFKcWQek3L } QmZtEaT7KTd1w2uzL46xMscjXMgwxupgy1chpPKHvdSbzC bump version 0.2 { QmYWcu4VkcQ7vvugSqJuwsVLwLijfhDj7UGyae2a8V1xY3, QmcoQ6WHtjrFi6x1JB6VBLDEYzfgxaM9mYwXRJ953M2SJ8 } QmYJStDEEPBWRU85G5N55585LroCaf1axK1ynKLR9gcaFh add feature { QmZtEaT7KTd1w2uzL46xMscjXMgwxupgy1chpPKHvdSbzC } Qme9Dqbu98VsdvmJvbpnbcKeUkh4d332BFxiCMJFFEU1Dj add spanish translation { QmYJStDEEPBWRU85G5N55585LroCaf1axK1ynKLR9gcaFh } Qmcuv6bvnVbahziieBb28oR8E6TpgRWyX3vzWu4MgWyVHa add chinese translation { QmYJStDEEPBWRU85G5N55585LroCaf1axK1ynKLR9gcaFh } QmRrX4qyaZX8wMTkjfHLbT8erD6Hz6suzZvDA4LbTcL646 fix i18n api { Qmcuv6bvnVbahziieBb28oR8E6TpgRWyX3vzWu4MgWyVHa, Qme9Dqbu98VsdvmJvbpnbcKeUkh4d332BFxiCMJFFEU1Dj } QmSRozfJqeznzV7j1tL8LbTyPGHRAhFoqaBGsmzbRyReqh add i18n feature { QmRrX4qyaZX8wMTkjfHLbT8erD6Hz6suzZvDA4LbTcL646 } QmRBzEJQ3eDaKVh9dM6XhrQ1GgMSRm6uge8M7itkHUhorE add afrikaans translation { QmYJStDEEPBWRU85G5N55585LroCaf1axK1ynKLR9gcaFh } QmPse7WVT7ftSpvcMPXCfTPjehwigDaSMsaePpgtjANzzy version bump 0.3 { QmRBzEJQ3eDaKVh9dM6XhrQ1GgMSRm6uge8M7itkHUhorE, QmSRozfJqeznzV7j1tL8LbTyPGHRAhFoqaBGsmzbRyReqh }
func (*CoLog) Join ¶
Join merges colog `other' into `l'
Example (One) ¶
var log1 = New(ipfsdb) var log2 = New(ipfsdb) log1.Add(value1) log2.Add(value2) log1.Join(log2) items := log1.Items() first := items[0] second := items[1] fmt.Println(len(items)) fmt.Println(first.Hash) fmt.Println(second.Hash) fmt.Println(string(first.GetString())) fmt.Println(string(second.GetString()))
Output: 2 QmbiruS6UMT6gT3JBHtZNWKitEssyUQzYu8k4gGd6rhzNc QmXgHKWQEG6NwpqJMvvvBdMrzWqPNo6cLtZr4BpZHFvrXV Hello1 Hello2
func (*CoLog) Unwatch ¶
Unwatch drops channel ch from the list of channels that are being written to
Example ¶
l1 := New(ipfsdb)
l2 := New(ipfsdb)
ch := l1.Watch()
wait := make(chan struct{})
go func() {
for e := range ch {
fmt.Println(e.GetString())
wait <- struct{}{}
}
}()
l1.Add("abcdef")
<-wait
ch2 := l1.Watch()
l1.Unwatch(ch)
l2.Join(l1)
l2.Add("ghijk")
l1.Join(l2)
<-ch2
fmt.Println(l1.chans.Count())
Output: abcdef 1
func (*CoLog) Watch ¶
Watch returns an Entry chan, notifying you of additions to the log
Example ¶
l1 := New(ipfsdb)
l2 := New(ipfsdb)
l3 := New(ipfsdb)
l4 := New(ipfsdb)
ch := l1.Watch()
wait := make(chan struct{})
go func() {
for e := range ch {
fmt.Println(e.GetString())
wait <- struct{}{}
}
}()
l1.Add("abcdef")
<-wait
l2.Join(l1)
l2.Add("ghijk")
l1.Join(l2)
<-wait
l3.Join(l1)
e3 := checkadd(l3.Add("lmnop"))
l1.FetchFromHead(e3.Hash)
<-wait
e4 := checkadd(l4.Add("qrstu"))
l1.FetchFromHead(e4.Hash)
<-wait
Output: abcdef ghijk lmnop qrstu
type Entry ¶
type Entry struct {
Hash Hash `json:"-"`
Value json.RawMessage `json:"payload"`
Prev HashSet `json:"next"`
}
Entry is an element of the log.
func (*Entry) Get ¶
Get writes the value that is serialized in the entry into v. v needs to be a pointer.
type HashSet ¶
type HashSet map[Hash]struct{}
HashSet is a set of Hashes
func (HashSet) MarshalJSON ¶
MarshalJSON returns the JSON representation of the set
func (HashSet) UnmarshalJSON ¶
UnmarshalJSON adds hashes from JSON (usually called on empty sets)
type Index ¶
Index maps a hash to a set of hashes.
type Query ¶
type Query struct {
Before, After QueryBound
}
Query defines which part of the colog should be queried
type QueryBound ¶
QueryBound defines a bound for a query.
Source Files
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