1 files changed, 63 insertions, 1 deletions
diff --git a/lua/clever_f/acquisition_service.lua b/lua/clever_f/acquisition_service.lua
index f8181dd..5f15fa1 100644
--- a/lua/clever_f/acquisition_service.lua
+++ b/lua/clever_f/acquisition_service.lua
@@ -3,15 +3,18 @@ local domain = require("clever_f.domain")
 local M = {}
 local AcquisitionRequest = {}
 local AcquisitionService = {}
+local TemporaryResourceScope = {}
 AcquisitionService.__index = AcquisitionService
 M.AcquisitionRequest = AcquisitionRequest
 M.AcquisitionService = AcquisitionService
+M.TemporaryResourceScope = TemporaryResourceScope
 M.RepeatedDirection = {
   SAME = "same",
 }
 
 local request_records = setmetatable({}, { __mode = "k" })
 local service_records = setmetatable({}, { __mode = "k" })
+local scope_records = setmetatable({}, { __mode = "k" })
 
 local function fail(message, level)
   error(message, (level or 1) + 1)
@@ -81,6 +84,44 @@ function AcquisitionRequest:to_table()
   }
 end
 
+local scope_metatable = {
+  __index = function(scope, key)
+    local method = TemporaryResourceScope[key]
+    if method ~= nil then
+      return method
+    end
+    return scope_records[scope][key]
+  end,
+  __newindex = function()
+    fail("TemporaryResourceScope values are read-only", 2)
+  end,
+  __metatable = "clever_f.acquisition_service.TemporaryResourceScope",
+}
+
+function TemporaryResourceScope.new(request)
+  if not AcquisitionRequest.is(request) then
+    fail("temporary resource scope requires an AcquisitionRequest", 2)
+  end
+  local scope = setmetatable({}, scope_metatable)
+  scope_records[scope] = {
+    request = request,
+    active = true,
+  }
+  return scope
+end
+
+function TemporaryResourceScope.is(value)
+  return type(value) == "table" and scope_records[value] ~= nil
+end
+
+function TemporaryResourceScope:release()
+  local record = scope_records[self]
+  if record == nil then
+    fail("temporary resource scope is invalid", 2)
+  end
+  record.active = false
+end
+
 local function normalize_options(options, dependencies)
   if AcquisitionService.is(options) and dependencies == nil then
     return options
@@ -113,6 +154,8 @@ function AcquisitionService.new(options, dependencies)
   local service = setmetatable({}, AcquisitionService)
   service_records[service] = {
     host = options.host,
+    last_scope = nil,
+    started_scope_count = 0,
   }
   return service
 end
@@ -125,8 +168,27 @@ function AcquisitionService:request(descriptor, context, position, count, macro_
   return AcquisitionRequest.new(descriptor, context, position, count, macro_state)
 end
 
+function AcquisitionService:start_temporary_scope(request)
+  request = AcquisitionRequest.new(request)
+  local record = service_records[self]
+  local scope = TemporaryResourceScope.new(request)
+  record.last_scope = scope
+  record.started_scope_count = record.started_scope_count + 1
+  return scope
+end
+
+function AcquisitionService:last_temporary_scope()
+  return service_records[self].last_scope
+end
+
+function AcquisitionService:started_scope_count()
+  return service_records[self].started_scope_count
+end
+
 function AcquisitionService:acquire(descriptor, context, position, count, macro_state)
-  return self:request(descriptor, context, position, count, macro_state)
+  local request = self:request(descriptor, context, position, count, macro_state)
+  self:start_temporary_scope(request)
+  return request
 end
 
 function M.new(options, dependencies)