mirror of https://github.com/tidwall/buntdb.git
Fix code formatting
This commit is contained in:
Josh Baker
GitHub
parent
75d89283d5
commit
847243a6cf
234
README.md
234
README.md
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@ -56,20 +56,20 @@ database, use the `buntdb.Open()` function:
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package main
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import (
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"log"
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"log"
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"github.com/tidwall/buntdb"
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"github.com/tidwall/buntdb"
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)
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func main() {
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// Open the data.db file. It will be created if it doesn't exist.
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db, err := buntdb.Open("data.db")
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if err != nil {
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log.Fatal(err)
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}
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defer db.Close()
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// Open the data.db file. It will be created if it doesn't exist.
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db, err := buntdb.Open("data.db")
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if err != nil {
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log.Fatal(err)
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}
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defer db.Close()
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...
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...
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}
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```
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@ -91,8 +91,8 @@ A read-only transaction should be used when you don't need to make changes to th
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```go
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err := db.View(func(tx *buntdb.Tx) error {
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...
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return nil
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...
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return nil
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})
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```
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@ -101,8 +101,8 @@ A read/write transaction is used when you need to make changes to your data. The
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```go
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err := db.Update(func(tx *buntdb.Tx) error {
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...
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return nil
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...
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return nil
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})
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```
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@ -112,8 +112,8 @@ To set a value you must open a read/write transaction:
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```go
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err := db.Update(func(tx *buntdb.Tx) error {
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_, _, err := tx.Set("mykey", "myvalue", nil)
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return err
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_, _, err := tx.Set("mykey", "myvalue", nil)
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return err
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})
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```
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@ -122,12 +122,12 @@ To get the value:
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```go
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err := db.View(func(tx *buntdb.Tx) error {
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val, err := tx.Get("mykey")
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if err != nil{
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return err
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}
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fmt.Printf("value is %s\n", val)
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return nil
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val, err := tx.Get("mykey")
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if err != nil{
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return err
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}
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fmt.Printf("value is %s\n", val)
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return nil
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})
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```
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@ -138,18 +138,16 @@ All keys/value pairs are ordered in the database by the key. To iterate over the
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```go
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err := db.View(func(tx *buntdb.Tx) error {
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err := tx.Ascend("", func(key, value string) bool {
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fmt.Printf("key: %s, value: %s\n", key, value)
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})
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return err
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err := tx.Ascend("", func(key, value string) bool {
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fmt.Printf("key: %s, value: %s\n", key, value)
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})
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return err
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})
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```
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There is also `AscendGreaterOrEqual`, `AscendLessThan`, `AscendRange`, `AscendEqual`, `Descend`, `DescendLessOrEqual`, `DescendGreaterThan`, `DescendRange`, and `DescendEqual`. Please see the [documentation](https://godoc.org/github.com/tidwall/buntdb) for more information on these functions.
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## Custom Indexes
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Initially all data is stored in a single [B-tree](https://en.wikipedia.org/wiki/B-tree) with each item having one key and one value. All of these items are ordered by the key. This is great for quickly getting a value from a key or [iterating](#iterating) over the keys. Feel free to peruse the [B-tree implementation](https://github.com/tidwall/btree).
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@ -167,14 +165,14 @@ Now you can add various names:
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```go
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db.Update(func(tx *buntdb.Tx) error {
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tx.Set("user:0:name", "tom", nil)
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tx.Set("user:1:name", "Randi", nil)
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tx.Set("user:2:name", "jane", nil)
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tx.Set("user:4:name", "Janet", nil)
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tx.Set("user:5:name", "Paula", nil)
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tx.Set("user:6:name", "peter", nil)
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tx.Set("user:7:name", "Terri", nil)
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return nil
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tx.Set("user:0:name", "tom", nil)
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tx.Set("user:1:name", "Randi", nil)
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tx.Set("user:2:name", "jane", nil)
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tx.Set("user:4:name", "Janet", nil)
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tx.Set("user:5:name", "Paula", nil)
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tx.Set("user:6:name", "peter", nil)
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tx.Set("user:7:name", "Terri", nil)
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return nil
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})
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```
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@ -182,11 +180,11 @@ Finally you can iterate over the index:
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```go
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db.View(func(tx *buntdb.Tx) error {
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tx.Ascend("names", func(key, val string) bool {
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fmt.Printf(buf, "%s %s\n", key, val)
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return true
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})
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return nil
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tx.Ascend("names", func(key, val string) bool {
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fmt.Printf(buf, "%s %s\n", key, val)
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return true
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})
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return nil
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})
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```
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The output should be:
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@ -223,24 +221,24 @@ And then add values:
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```go
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db.Update(func(tx *buntdb.Tx) error {
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tx.Set("user:0:age", "35", nil)
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tx.Set("user:1:age", "49", nil)
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tx.Set("user:2:age", "13", nil)
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tx.Set("user:4:age", "63", nil)
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tx.Set("user:5:age", "8", nil)
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tx.Set("user:6:age", "3", nil)
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tx.Set("user:7:age", "16", nil)
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return nil
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tx.Set("user:0:age", "35", nil)
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tx.Set("user:1:age", "49", nil)
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tx.Set("user:2:age", "13", nil)
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tx.Set("user:4:age", "63", nil)
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tx.Set("user:5:age", "8", nil)
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tx.Set("user:6:age", "3", nil)
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tx.Set("user:7:age", "16", nil)
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return nil
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})
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```
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```go
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db.View(func(tx *buntdb.Tx) error {
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tx.Ascend("ages", func(key, val string) bool {
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fmt.Printf(buf, "%s %s\n", key, val)
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return true
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})
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return nil
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tx.Ascend("ages", func(key, val string) bool {
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fmt.Printf(buf, "%s %s\n", key, val)
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return true
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})
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return nil
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})
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```
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@ -270,10 +268,10 @@ To add some lon,lat points to the `fleet` index:
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```go
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db.Update(func(tx *buntdb.Tx) error {
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tx.Set("fleet:0:pos", "[-115.567 33.532]", nil)
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tx.Set("fleet:1:pos", "[-116.671 35.735]", nil)
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tx.Set("fleet:2:pos", "[-113.902 31.234]", nil)
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return nil
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tx.Set("fleet:0:pos", "[-115.567 33.532]", nil)
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tx.Set("fleet:1:pos", "[-116.671 35.735]", nil)
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tx.Set("fleet:2:pos", "[-113.902 31.234]", nil)
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return nil
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})
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```
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@ -281,11 +279,11 @@ And then you can run the `Intersects` function on the index:
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```go
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db.View(func(tx *buntdb.Tx) error {
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tx.Intersects("fleet", "[-117 30],[-112 36]", func(key, val string) bool {
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...
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return true
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})
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return nil
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tx.Intersects("fleet", "[-117 30],[-112 36]", func(key, val string) bool {
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...
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return true
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})
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return nil
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})
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```
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@ -297,11 +295,11 @@ Use the `Nearby` function to get all the positions in order of nearest to farthe
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```go
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db.View(func(tx *buntdb.Tx) error {
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tx.Nearby("fleet", "[-113 33]", func(key, val string, dist float64) bool {
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...
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return true
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})
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return nil
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tx.Nearby("fleet", "[-113 33]", func(key, val string, dist float64) bool {
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...
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return true
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})
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return nil
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})
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```
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@ -341,8 +339,8 @@ You can then do a search for all points with `M` between 2-4 by calling `Interse
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```go
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tx.Intersects("points", "[-inf -inf 2],[+inf +inf 4]", func(key, val string) bool {
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println(val)
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return true
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println(val)
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return true
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})
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```
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@ -363,40 +361,40 @@ For example:
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package main
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import (
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"fmt"
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"fmt"
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"github.com/tidwall/buntdb"
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"github.com/tidwall/buntdb"
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)
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func main() {
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db, _ := buntdb.Open(":memory:")
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db.CreateIndex("last_name", "*", buntdb.IndexJSON("name.last"))
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db.CreateIndex("age", "*", buntdb.IndexJSON("age"))
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db.Update(func(tx *buntdb.Tx) error {
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tx.Set("1", `{"name":{"first":"Tom","last":"Johnson"},"age":38}`, nil)
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tx.Set("2", `{"name":{"first":"Janet","last":"Prichard"},"age":47}`, nil)
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tx.Set("3", `{"name":{"first":"Carol","last":"Anderson"},"age":52}`, nil)
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tx.Set("4", `{"name":{"first":"Alan","last":"Cooper"},"age":28}`, nil)
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return nil
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})
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db.View(func(tx *buntdb.Tx) error {
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fmt.Println("Order by last name")
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tx.Ascend("last_name", func(key, value string) bool {
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fmt.Printf("%s: %s\n", key, value)
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return true
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})
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fmt.Println("Order by age")
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tx.Ascend("age", func(key, value string) bool {
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fmt.Printf("%s: %s\n", key, value)
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return true
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})
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fmt.Println("Order by age range 30-50")
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tx.AscendRange("age", `{"age":30}`, `{"age":50}`, func(key, value string) bool {
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fmt.Printf("%s: %s\n", key, value)
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return true
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})
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return nil
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})
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db, _ := buntdb.Open(":memory:")
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db.CreateIndex("last_name", "*", buntdb.IndexJSON("name.last"))
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db.CreateIndex("age", "*", buntdb.IndexJSON("age"))
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db.Update(func(tx *buntdb.Tx) error {
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tx.Set("1", `{"name":{"first":"Tom","last":"Johnson"},"age":38}`, nil)
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tx.Set("2", `{"name":{"first":"Janet","last":"Prichard"},"age":47}`, nil)
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tx.Set("3", `{"name":{"first":"Carol","last":"Anderson"},"age":52}`, nil)
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tx.Set("4", `{"name":{"first":"Alan","last":"Cooper"},"age":28}`, nil)
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return nil
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})
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db.View(func(tx *buntdb.Tx) error {
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fmt.Println("Order by last name")
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tx.Ascend("last_name", func(key, value string) bool {
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fmt.Printf("%s: %s\n", key, value)
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return true
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})
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fmt.Println("Order by age")
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tx.Ascend("age", func(key, value string) bool {
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fmt.Printf("%s: %s\n", key, value)
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return true
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})
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fmt.Println("Order by age range 30-50")
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tx.AscendRange("age", `{"age":30}`, `{"age":50}`, func(key, value string) bool {
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fmt.Printf("%s: %s\n", key, value)
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return true
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})
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return nil
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})
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}
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```
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@ -430,20 +428,20 @@ In this example we are creating a multi value index on "name.last" and "age":
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db, _ := buntdb.Open(":memory:")
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db.CreateIndex("last_name_age", "*", buntdb.IndexJSON("name.last"), buntdb.IndexJSON("age"))
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db.Update(func(tx *buntdb.Tx) error {
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tx.Set("1", `{"name":{"first":"Tom","last":"Johnson"},"age":38}`, nil)
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tx.Set("2", `{"name":{"first":"Janet","last":"Prichard"},"age":47}`, nil)
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tx.Set("3", `{"name":{"first":"Carol","last":"Anderson"},"age":52}`, nil)
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tx.Set("4", `{"name":{"first":"Alan","last":"Cooper"},"age":28}`, nil)
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tx.Set("5", `{"name":{"first":"Sam","last":"Anderson"},"age":51}`, nil)
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tx.Set("6", `{"name":{"first":"Melinda","last":"Prichard"},"age":44}`, nil)
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return nil
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tx.Set("1", `{"name":{"first":"Tom","last":"Johnson"},"age":38}`, nil)
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tx.Set("2", `{"name":{"first":"Janet","last":"Prichard"},"age":47}`, nil)
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tx.Set("3", `{"name":{"first":"Carol","last":"Anderson"},"age":52}`, nil)
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tx.Set("4", `{"name":{"first":"Alan","last":"Cooper"},"age":28}`, nil)
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tx.Set("5", `{"name":{"first":"Sam","last":"Anderson"},"age":51}`, nil)
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tx.Set("6", `{"name":{"first":"Melinda","last":"Prichard"},"age":44}`, nil)
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return nil
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})
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db.View(func(tx *buntdb.Tx) error {
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tx.Ascend("last_name_age", func(key, value string) bool {
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fmt.Printf("%s: %s\n", key, value)
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return true
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})
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return nil
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tx.Ascend("last_name_age", func(key, value string) bool {
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fmt.Printf("%s: %s\n", key, value)
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return true
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})
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return nil
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})
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// Output:
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@ -459,9 +457,9 @@ db.View(func(tx *buntdb.Tx) error {
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Any index can be put in descending order by wrapping it's less function with `buntdb.Desc`.
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```go
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db.CreateIndex("last_name_age", "*",
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buntdb.IndexJSON("name.last"),
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buntdb.Desc(buntdb.IndexJSON("age")))
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db.CreateIndex("last_name_age", "*",
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buntdb.IndexJSON("name.last"),
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buntdb.Desc(buntdb.IndexJSON("age")))
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```
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This will create a multi value index where the last name is ascending and the age is descending.
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@ -503,8 +501,8 @@ Items can be automatically evicted by using the `SetOptions` object in the `Set`
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```go
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db.Update(func(tx *buntdb.Tx) error {
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tx.Set("mykey", "myval", &buntdb.SetOptions{Expires:true, TTL:time.Second})
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return nil
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tx.Set("mykey", "myval", &buntdb.SetOptions{Expires:true, TTL:time.Second})
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return nil
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})
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```
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@ -576,10 +574,10 @@ To update the configuration you should call `ReadConfig` followed by `SetConfig`
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var config buntdb.Config
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if err := db.ReadConfig(&config); err != nil{
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log.Fatal(err)
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log.Fatal(err)
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}
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if err := db.WriteConfig(config); err != nil{
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log.Fatal(err)
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log.Fatal(err)
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}
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```
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