c1c0c77ddc
- an unexported reserver (Reserve, Release) next to updater: the memory store reserves under its mutex, the Redis store in one Lua script (prune, SCARD, SET PX plus SADD); serveNew reserves instead of Count then Put and releases on a failed connect or initialize (A-WR-03) - serveNew, lookup's rehydration and the stateless getServer build the SDK server with no router-wide lock held and insert or adopt under the lock afterwards, so a slow guard or database check no longer stalls the instance (A-WR-07)
66 lines
2.7 KiB
Go
66 lines
2.7 KiB
Go
package pier
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import (
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"context"
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"encoding/json"
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"time"
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)
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// Record is one stored session: the binding key of the identity that opened
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// it, the JSON of the SDK's ServerSessionState once initialised (nil until
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// then) and the creation time.
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type Record struct {
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Binding string `json:"binding"`
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State json.RawMessage `json:"state,omitempty"`
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Created time.Time `json:"created"`
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}
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// Event is what instances publish to each other: a session ended by DELETE
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// (EventEnded, with SessionID) or a subject change (the pact
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// MCPSubjectChanged kinds, with Guard and UserID). Instance names the
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// publisher so it can skip its own echo when it has already acted.
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type Event struct {
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Kind string `json:"kind"`
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Guard string `json:"guard,omitempty"`
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UserID uint `json:"user_id,omitempty"`
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SessionID string `json:"session_id,omitempty"`
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Instance string `json:"instance,omitempty"`
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}
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// EventEnded is the kind of a session-ended event.
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const EventEnded = "ended"
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// Store is the session registry and the event channel shared by every
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// instance of the application: memory for one instance (and tests), Redis
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// for several. Put writes a record with a TTL, Touch slides it, Count
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// answers the live sessions of one binding, Publish and Subscribe carry
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// Events.
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type Store interface {
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Put(ctx context.Context, id string, rec Record, ttl time.Duration) error
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Get(ctx context.Context, id string) (Record, bool, error)
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Touch(ctx context.Context, id string, ttl time.Duration) error
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Delete(ctx context.Context, id string) error
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Count(ctx context.Context, binding string) (int, error)
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Publish(ctx context.Context, ev Event) error
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Subscribe(ctx context.Context, fn func(Event)) error
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}
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// updater is implemented by the stores pier ships: Update rewrites an
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// existing record and never creates one (Redis SET XX), answering false when
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// the record is gone, so a request that finishes after its session ended
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// (DELETE, revocation, deletion, expiry) cannot write the record back.
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type updater interface {
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Update(ctx context.Context, id string, rec Record, ttl time.Duration) (bool, error)
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}
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// reserver is implemented by the stores pier ships: Reserve is the atomic
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// form of Count then Put (A-WR-03). It writes rec for id with the TTL and
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// adds id to the binding's sessions only when the binding holds fewer than
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// max live sessions, answering false (nothing written) at the cap, so
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// concurrent initializes of one binding cannot exceed it. Release drops a
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// reservation whose session never opened (a failed connect or initialize).
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type reserver interface {
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Reserve(ctx context.Context, binding, id string, rec Record, max int, ttl time.Duration) (bool, error)
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Release(ctx context.Context, binding, id string) error
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}
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