db: add json writer functionality

This introduces a dependency on the cjson library.

1 files changed, 43 insertions, 0 deletions

diff --git a/db.lua b/db.lua
new file mode 100644
index 0000000..4e7434a
--- /dev/null
+++ b/db.lua
@@ -0,0 +1,43 @@
+--[[--
+
+  JSON file database.
+
+--]]--
+
+local inspect = require "ext.inspect"
+
+local cjson               = require "cjson"
+
+local pcall               = pcall
+
+local io                  = require "io"
+local iostdout            = io.stdout
+
+local common              = require "common"
+local common_status       = common.status
+local status_ok           = common_status.codes.ok
+local status_error        = common_status.codes.error
+local println             = common.println
+local errorln             = common.errorln
+local noiseln             = common.noiseln
+local debugln             = common.debugln
+
+-------------------------------------------------------------------------------
+--- API
+-------------------------------------------------------------------------------
+
+local output_calendar = function (cal, fh)
+  fh = fh or iostdout
+  local jsenc = cjson.new ()
+  local ok, str = pcall (jsenc.encode, cal)
+  if ok == false then
+          errorln ("todb: failed to serialize calendar: %s", str)
+    return status_error
+  end
+  fh:write (str)
+  return status_ok
+end
+
+return { output_calendar = output_calendar
+       }
+