dotcloud/docker

package defaultipam

import (
    "fmt"
    "net/netip"
    "strings"

    "github.com/docker/docker/libnetwork/bitmap"
    "github.com/docker/docker/libnetwork/types"
)

// PoolID is the pointer to the configured pools in each address space
type PoolID struct {
    AddressSpace string
    SubnetKey
}

// PoolData contains the configured pool data
type PoolData struct {
    addrs    *bitmap.Bitmap
    children map[netip.Prefix]struct{}

    // Whether to implicitly release the pool once it no longer has any children.
    autoRelease bool
}

// SubnetKey is the composite key to an address pool within an address space.
type SubnetKey struct {
    Subnet, ChildSubnet netip.Prefix
}

func (k SubnetKey) Is6() bool {
    return k.Subnet.Addr().Is6()
}

// PoolIDFromString creates a new PoolID and populates the SubnetKey object
// reading it from the given string.
func PoolIDFromString(str string) (pID PoolID, err error) {
    if str == "" {
        return pID, types.InvalidParameterErrorf("invalid string form for subnetkey: %s", str)
    }

    p := strings.Split(str, "/")
    if len(p) != 3 && len(p) != 5 {
        return pID, types.InvalidParameterErrorf("invalid string form for subnetkey: %s", str)
    }
    pID.AddressSpace = p[0]
    pID.Subnet, err = netip.ParsePrefix(p[1] + "/" + p[2])
    if err != nil {
        return pID, types.InvalidParameterErrorf("invalid string form for subnetkey: %s", str)
    }
    if len(p) == 5 {
        pID.ChildSubnet, err = netip.ParsePrefix(p[3] + "/" + p[4])
        if err != nil {
            return pID, types.InvalidParameterErrorf("invalid string form for subnetkey: %s", str)
        }
    }

    return pID, nil
}

// String returns the string form of the SubnetKey object
func (s *PoolID) String() string {
    if s.ChildSubnet == (netip.Prefix{}) {
        return s.AddressSpace + "/" + s.Subnet.String()
    } else {
        return s.AddressSpace + "/" + s.Subnet.String() + "/" + s.ChildSubnet.String()
    }
}

// String returns the string form of the PoolData object
func (p *PoolData) String() string {
    return fmt.Sprintf("PoolData[Children: %d]", len(p.children))
}

// mergeIter is used to iterate on both 'a' and 'b' at the same time while
// maintaining the total order that would arise if both were merged and then
// sorted. Both 'a' and 'b' have to be sorted beforehand.
type mergeIter struct {
    a, b   []netip.Prefix
    ia, ib int
    cmp    func(a, b netip.Prefix) int
    lastA  bool
}

func newMergeIter(a, b []netip.Prefix, cmp func(a, b netip.Prefix) int) *mergeIter {
    iter := &mergeIter{
        a:   a,
        b:   b,
        cmp: cmp,
    }
    iter.lastA = iter.nextA()

    return iter
}

func (it *mergeIter) Get() netip.Prefix {
    if it.ia+it.ib >= len(it.a)+len(it.b) {
        return netip.Prefix{}
    }

    if it.lastA {
        return it.a[it.ia]
    }

    return it.b[it.ib]
}

func (it *mergeIter) Inc() {
    if it.lastA {
        it.ia++
    } else {
        it.ib++
    }

    it.lastA = it.nextA()
}

func (it *mergeIter) nextA() bool {
    if it.ia < len(it.a) && it.ib < len(it.b) && it.cmp(it.a[it.ia], it.b[it.ib]) <= 0 {
        return true
    } else if it.ia < len(it.a) && it.ib >= len(it.b) {
        return true
    }

    return false
}