diff options
Diffstat (limited to 'swarm/api/api.go')
-rw-r--r-- | swarm/api/api.go | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/swarm/api/api.go b/swarm/api/api.go index 79de29a1c..d0c3754e0 100644 --- a/swarm/api/api.go +++ b/swarm/api/api.go @@ -17,6 +17,7 @@ package api import ( + "errors" "fmt" "io" "net/http" @@ -40,6 +41,69 @@ type Resolver interface { Resolve(string) (common.Hash, error) } +// errNoResolver is returned by MultiResolver.Resolve if no resolver +// can be found for the address. +var errNoResolver = errors.New("no resolver") + +// MultiResolver is used to resolve URL addresses based on their TLDs. +// Each TLD can have multiple resolvers, and the resoluton from the +// first one in the sequence will be returned. +type MultiResolver struct { + resolvers map[string][]Resolver +} + +// MultiResolverOption sets options for MultiResolver and is used as +// arguments for its constructor. +type MultiResolverOption func(*MultiResolver) + +// MultiResolverOptionWithResolver adds a Resolver to a list of resolvers +// for a specific TLD. If TLD is an empty string, the resolver will be added +// to the list of default resolver, the ones that will be used for resolution +// of addresses which do not have their TLD resolver specified. +func MultiResolverOptionWithResolver(r Resolver, tld string) MultiResolverOption { + return func(m *MultiResolver) { + if _, ok := m.resolvers[tld]; !ok { + m.resolvers[tld] = []Resolver{} + } + m.resolvers[tld] = append(m.resolvers[tld], r) + } +} + +// NewMultiResolver creates a new instance of MultiResolver. +func NewMultiResolver(opts ...MultiResolverOption) (m *MultiResolver) { + m = &MultiResolver{ + resolvers: map[string][]Resolver{}, + } + for _, o := range opts { + o(m) + } + return m +} + +// Resolve resolves address by choosing a Resolver by TLD. +// If there are more default Resolvers, or for a specific TLD, +// the Hash from the the first one which does not return error +// will be returned. +func (m MultiResolver) Resolve(addr string) (h common.Hash, err error) { + rs, _ := m.resolvers[""] + if i := strings.LastIndex(addr, "."); i >= 0 { + rstld, ok := m.resolvers[addr[i+1:]] + if ok { + rs = rstld + } + } + if rs == nil { + return h, errNoResolver + } + for _, r := range rs { + h, err = r.Resolve(addr) + if err == nil { + return + } + } + return +} + /* Api implements webserver/file system related content storage and retrieval on top of the dpa |