Harmon
747eed63b0
A Go service that scans existing basemap tile directories and vector files, catalogues them in SQLite, issues scoped access tokens, and serves tiles and downloads to downstream systems. It deliberately does not generate or process raster data: GIS software produces the tiles, this service catalogues, authorises and distributes them. Capabilities - scans basemap tile directories (manifest-based or raw z/x/y) and vector assets (.geojson, .json, .zip, shapefiles with sidecars) - token auth with per-resource grants, expiry and coarse scopes (read, slice) - resource health inspection flags a moved or deleted tile root before a client hits a 404 - downstream push with exponential-backoff retries and manual re-queue - image slicing jobs driven by the GDAL bundled with QGIS, including VRT mosaicking so successive drone flights accumulate into one seamless layer - a narrow, non-admin slicing API for external callers: submit, poll, idempotent by job code, completion callback - ops console covering health, ledger, tokens, pushes, scans, slicing and service info - native Windows service install/start/stop with crash recovery, auto-start and a rotating log file, so no NSSM or WinSW wrapper is needed Verified with 49 tests plus live runs against real tile data and real GDAL.
99 lines
2.2 KiB
Go
99 lines
2.2 KiB
Go
package basemap
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import (
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"context"
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"log"
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"time"
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)
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const (
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// pushRetryInterval is how often due retries are looked for.
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pushRetryInterval = 15 * time.Second
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// tileJobInterval is how often the queue is checked for new jobs.
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tileJobInterval = 2 * time.Second
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)
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// StartBackgroundWorkers launches the periodic maintenance loops: resource
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// health inspection, push retries and the tile slicing queue. Close stops them.
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// Calling it more than once has no additional effect.
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func (s *Store) StartBackgroundWorkers() {
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s.bgOnce.Do(func() {
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ctx, cancel := context.WithCancel(context.Background())
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s.bgCtx = ctx
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s.bgCancel = cancel
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s.bgWG.Add(1)
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go func() {
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defer s.bgWG.Done()
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s.healthLoop(ctx)
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}()
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s.bgWG.Add(1)
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go func() {
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defer s.bgWG.Done()
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s.pushRetryLoop(ctx)
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}()
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s.bgWG.Add(1)
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go func() {
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defer s.bgWG.Done()
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s.tileJobLoop(ctx)
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}()
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})
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}
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func (s *Store) healthLoop(ctx context.Context) {
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// Prime the catalog immediately so a resource that vanished since the last
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// scan shows up without waiting a full interval.
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if _, err := s.CheckHealth(ctx); err != nil && ctx.Err() == nil {
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log.Printf("health check failed: %v", err)
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}
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interval := s.cfg.HealthCheckInterval
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if interval <= 0 {
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return
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}
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ticker := time.NewTicker(interval)
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defer ticker.Stop()
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for {
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select {
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case <-ctx.Done():
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return
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case <-ticker.C:
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if _, err := s.CheckHealth(ctx); err != nil && ctx.Err() == nil {
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log.Printf("health check failed: %v", err)
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}
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}
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}
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}
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func (s *Store) pushRetryLoop(ctx context.Context) {
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ticker := time.NewTicker(pushRetryInterval)
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defer ticker.Stop()
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for {
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select {
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case <-ctx.Done():
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return
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case <-ticker.C:
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if err := s.dispatchPushRetries(ctx); err != nil && ctx.Err() == nil {
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log.Printf("push retry dispatch failed: %v", err)
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}
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if err := s.dispatchTileJobCallbacks(ctx); err != nil && ctx.Err() == nil {
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log.Printf("tile job callback dispatch failed: %v", err)
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}
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}
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}
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}
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func (s *Store) tileJobLoop(ctx context.Context) {
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ticker := time.NewTicker(tileJobInterval)
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defer ticker.Stop()
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for {
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s.dispatchTileJobs(ctx)
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select {
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case <-ctx.Done():
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return
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case <-ticker.C:
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}
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}
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}
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