🏠 persiting downloaded tiles in $home/.mapscii/cache/

README.md

@@ -50,29 +50,33 @@ No web browser around? Don't worry - and discover the planet in your console!
 #### Handling the flow
 * [`bluebird`](https://github.com/petkaantonov/bluebird) for all the asynchronous [Promise](https://developer.mozilla.org/de/docs/Web/JavaScript/Reference/Global_Objects/Promise) magic
 * [`request-promise`](https://github.com/request/request-promise) for promisified HTTP request handling
+* [`userhome`](https://github.com/shama/userhome) to determine where to persist downloaded tiles
 
 ### TODOs
 * MapSCII
   * [ ] CLI support
-    * [ ] global linking for npm install -g
+    * [X] global linking for npm install -g
     * [ ] startup parameters
-      * [ ] Style
-      * [ ] center position
-      * [ ] POI filter?
+      * TileSource
         * [ ] VectorTile
         * [ ] MBTile
         * [ ] Tileserver
-  * [ ] mapscii-server
-    * [ ] telnet
-    * [ ] ssh
+      * [ ] Style
+      * [ ] center position
+      * [ ] POI filter?
   * [ ] Viewport
-    * [x] start with zoom level which shows full vector tile
+    * [x] start with zoom level which shows full
+      * [X] world
+      * [ ] vector tile
     * [X] boundary based on current zoom & size
     * [X] determain tiles to show
     * [X] zoom while keeping center
     * [ ] calculate tile areas
     * [X] center based on mercator
     * [x] handle console resize
+  * [ ] mapscii-server
+    * [ ] telnet
+    * [ ] ssh
   * [x] handle console resize
   * [ ] mouse control
     * [x] accurate mouse drag&drop with instant update
@@ -116,7 +120,7 @@ No web browser around? Don't worry - and discover the planet in your console!
     * [ ] from single vector-tile
     * [x] from local mbtiles
     * [x] from remote url
-      * [ ] permanent caching of received files
+      * [x] permanent caching of received files
 
 ## License
 #### The MIT License (MIT)

package.json

@@ -40,6 +40,7 @@
     "sphericalmercator": "^1.0.5",
     "term-mouse": "^0.1.1",
     "tilebelt": "^1.0.1",
+    "userhome": "^1.0.0",
     "vector-tile": "^1.3.0",
     "x256": "0.0.2"
   }

src/Renderer.coffee

@@ -7,7 +7,6 @@
 x256 = require 'x256'
 mercator = new (require('sphericalmercator'))()
 tilebelt = require 'tilebelt'
-MBTiles = require 'mbtiles'
 Promise = require 'bluebird'
 
 Canvas = require './Canvas'

src/TileSource.coffee

@@ -9,13 +9,17 @@
 
 Promise = require 'bluebird'
 MBTiles = require 'mbtiles'
-
+userhome = require 'userhome'
 request = require 'request'
 rp = require 'request-promise'
+fs = require 'fs'
 
 Tile = require './Tile'
 
 module.exports = class TileSource
+  config:
+    persistDownloadedTiles: true
+
   cache: {}
   modes:
     MBTiles: 1
@@ -28,6 +32,8 @@ module.exports = class TileSource
 
   init: (@source) ->
     if @source.startsWith "http"
+      @_initPersistence() if @config.persistDownloadedTiles
+
       @mode = @modes.HTTP
 
     else if @source.endsWith ".mbtiles"
@@ -57,9 +63,18 @@ module.exports = class TileSource
       when @modes.HTTP then @_getHTTP z, x, y
 
   _getHTTP: (z, x, y) ->
+    promise =
+      if @config.persistDownloadedTiles and tile = @_getPersited z, x, y
+        Promise.resolve tile
+      else
         rp
           uri: @source+[z,x,y].join("/")+".pbf"
           encoding: null
+        .then (buffer) =>
+          @_persistTile z, x, y, buffer if @config.persistDownloadedTiles
+          buffer
+
+    promise
     .then (buffer) =>
       @_createTile z, x, y, buffer
 
@@ -72,3 +87,29 @@ module.exports = class TileSource
   _createTile: (z, x, y, buffer) ->
     tile = @cache[[z,x,y].join("-")] = new Tile()
     tile.load buffer
+
+  _initPersistence: ->
+    try
+      @_createFolder userhome ".mapscii"
+      @_createFolder userhome ".mapscii", "cache"
+    catch error
+      @config.persistDownloadedTiles = false
+      return
+
+  _persistTile: (z, x, y, buffer) ->
+    zoom = z.toString()
+    @_createFolder userhome ".mapscii", "cache", zoom
+    fs.writeFile userhome(".mapscii", "cache", zoom, "#{x}-#{y}.pbf"), buffer
+
+  _getPersited: (z, x, y) ->
+    try
+      fs.readFileSync userhome ".mapscii", "cache", z.toString(), "#{x}-#{y}.pbf"
+    catch error
+      false
+
+  _createFolder: (path) ->
+    try
+      fs.mkdirSync path
+      true
+    catch e
+      e.code is "EEXIST"