Add Firebase base64 variant

README.md

@@ -1,6 +1,6 @@
 # Ecto.ULID
 
-An `Ecto.Type` implementation of [ULID](https://github.com/ulid/spec).
+An `Ecto.ParameterizedType` implementation of [ULID](https://github.com/ulid/spec).
 
 `Ecto.ULID` should be compatible anywhere that `Ecto.UUID` is supported. It has been confirmed to
 work with PostgreSQL and MySQL on Ecto 2.x and 3.x.  Ecto 1.x is *not* supported.
@@ -33,11 +33,11 @@ The following are results from running the benchmark on an AMD Ryzen Threadrippe
 
 ```
 benchmark name iterations   average time
-cast/1           10000000   0.25 µs/op
+cast/2           10000000   0.25 µs/op
 dump/1           10000000   0.50 µs/op
-load/1           10000000   0.55 µs/op
-bingenerate/0    10000000   0.93 µs/op
-generate/0        1000000   1.55 µs/op
+load/2           10000000   0.55 µs/op
+bingenerate/1    10000000   0.93 µs/op
+generate/2        1000000   1.55 µs/op
 ```
 
 ## Usage
@@ -106,9 +106,23 @@ end
 `Ecto.ULID` supports `autogenerate: true` as well as `autogenerate: false` when used as the primary
 key.
 
+`Ecto.ULID` also supports `variant: :b64` as well as `variant: :push` that follows the compact 20-char string encoding standard defined in [Firebase Push Key](https://firebase.googleblog.com/2015/02/the-2120-ways-to-ensure-unique_68.html). Just like the default Crockford base32 encoding, both variants use a modified base64 alphabet to ensure the IDs will still sort correctly when ordered lexicographically. Do note that the `:push` variant encodes only 120-bits, but is otherwise interoperable with the standard 128-bit binary ULID (by having the 1st-byte of the random component set to 0, we achieve a more efficient base64 encoding that saves 2 characters).
+
+```elixir
+defmodule MyApp.Event do
+  use Ecto.Schema
+
+  @primary_key {:id, Ecto.ULID, autogenerate: false, variant: :b64}
+  @foreign_key_type Ecto.ULID
+  schema "events" do
+    # more columns ...
+  end
+end
+```
+
 ### Application Usage
 
-A ULID can be generated in string or binary format by calling `generate/0` or `bingenerate/0`. This
+A ULID can be generated in string or binary format by calling `generate/2` or `bingenerate/1`. This
 can be useful when generating ULIDs to send to external systems:
 
 ```elixir

bench/ulid_bench.exs

@@ -1,25 +1,59 @@
 defmodule ULIDBench do
   use Benchfella
 
-  bench "generate/0" do
+  bench "generate/2" do
     Ecto.ULID.generate()
     nil
   end
 
-  bench "bingenerate/0" do
+  bench "generate/2 (:b64)" do
+    Ecto.ULID.generate(:b64)
+    nil
+  end
+
+  bench "generate/2 (:push)" do
+    Ecto.ULID.generate(:push)
+    nil
+  end
+
+  bench "bingenerate/1" do
     Ecto.ULID.bingenerate()
     nil
   end
 
-  bench "cast/1" do
+  bench "cast/2" do
     Ecto.ULID.cast("01C0M0Y7BG2NMB15VVVJH807F3")
   end
 
+  bench "cast/2 (:b64)" do
+    Ecto.ULID.cast("-0N1VE6M-KPA1MTxmXV0rY")
+  end
+
+  bench "cast/2 (:push)" do
+    Ecto.ULID.cast("-L-c2lpkPA1MTxmXV0rY")
+  end
+
   bench "dump/1" do
     Ecto.ULID.dump("01C0M0Y7BG2NMB15VVVJH807F3")
   end
 
-  bench "load/1" do
+  bench "dump/1 (:b64)" do
+    Ecto.ULID.dump("-0N1VE6M-KPA1MTxmXV0rY")
+  end
+
+  bench "dump/1 (:push)" do
+    Ecto.ULID.dump("-L-c2lpkPA1MTxmXV0rY")
+  end
+
+  bench "load/2" do
     Ecto.ULID.load(<<1, 96, 40, 15, 29, 112, 21, 104, 176, 151, 123, 220, 162, 128, 29, 227>>)
   end
+
+  bench "load/2 (:b64)" do
+    Ecto.ULID.load(<<1, 96, 40, 15, 29, 112, 21, 104, 176, 151, 123, 220, 162, 128, 29, 227>>, :b64)
+  end
+
+  bench "load/2 (:push)" do
+    Ecto.ULID.load(<<1, 96, 40, 15, 29, 112, 21, 104, 176, 151, 123, 220, 162, 128, 29, 227>>, :push)
+  end
 end