Bryan Boreham
72b30bc699
when granting a range that spans a token and inserting a new token, the free space on the last token that we are handing over has to change. Add unit test for this too.
61 lines
1.1 KiB
Go
61 lines
1.1 KiB
Go
package address
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import (
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"github.com/weaveworks/weave/common"
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"net"
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)
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// Using 32-bit integer to represent IPv4 address
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type Address uint32
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type Offset uint32
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type Range struct {
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Start, End Address // [Start, End); Start <= End
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}
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func ParseIP(s string) (Address, error) {
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if ip := net.ParseIP(s); ip != nil {
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return FromIP4(ip), nil
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}
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return 0, &net.ParseError{Type: "IP Address", Text: s}
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}
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// FromIP4 converts an ipv4 address to our integer address type
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func FromIP4(ip4 net.IP) (r Address) {
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for _, b := range ip4.To4() {
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r <<= 8
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r |= Address(b)
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}
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return
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}
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// IP4 converts our integer address type to an ipv4 address
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func (addr Address) IP4() (r net.IP) {
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r = make([]byte, net.IPv4len)
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for i := 3; i >= 0; i-- {
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r[i] = byte(addr)
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addr >>= 8
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}
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return
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}
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func (addr Address) String() string {
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return addr.IP4().String()
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}
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func Add(addr Address, i Offset) Address {
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return addr + Address(i)
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}
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func Subtract(a, b Address) Offset {
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common.Assert(a >= b)
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return Offset(a - b)
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}
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func Min(a, b Offset) Offset {
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if a > b {
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return b
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}
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return a
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}
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