1 files changed, 48 insertions, 0 deletions
diff --git a/script-beta/vm/getLinks.lua b/script-beta/vm/getLinks.lua
new file mode 100644
index 00000000..6875771f
--- /dev/null
+++ b/script-beta/vm/getLinks.lua
@@ -0,0 +1,48 @@
+local guide = require 'parser.guide'
+local vm    = require 'vm.vm'
+
+local function getLinks(root)
+    local cache = {}
+    local ok
+    guide.eachSpecialOf(root, 'require', function (source)
+        local call = source.parent
+        if call.type == 'call' then
+            local uris = vm.getLinkUris(call)
+            if uris then
+                ok = true
+                for i = 1, #uris do
+                    local uri = uris[i]
+                    if not cache[uri] then
+                        cache[uri] = {}
+                    end
+                    cache[uri][#cache[uri]+1] = call
+                end
+            end
+        end
+    end)
+    if not ok then
+        return nil
+    end
+    return cache
+end
+
+function vm.getLinks(source)
+    source = guide.getRoot(source)
+    local cache = vm.cache.getLinks[source]
+    if cache ~= nil then
+        return cache
+    end
+    local unlock = vm.lock('getLinks', source)
+    if not unlock then
+        return nil
+    end
+    local clock = os.clock()
+    cache = getLinks(source) or false
+    local passed = os.clock() - clock
+    if passed > 0.1 then
+        log.warn(('getLinks takes [%.3f] sec!'):format(passed))
+    end
+    vm.cache.getLinks[source] = cache
+    unlock()
+    return cache
+end