[Tarantool-patches] [PATCH] lua: introduce function for uuid comparison

[olegrok@tarantool.org]

From: Oleg Babin <babinoleg@mail.ru>

Since Tarantool has uuid data type sometimes we want to compare
uuid vaues as it's possible for primitive types and decimals. This
patch exports function for uuid comparison and implements le and
lt metamethods for uuid type.
To be consistent with decimal type this patch allows to compare
uuid with uuid string representation.

@TarantoolBot document Title: uuid compare

Currently comparison between uuid values is supported.
Example:
```lua
u1 = uuid.fromstr('aaaaaaaa-aaaa-4000-b000-000000000001')
u2 = uuid.fromstr('bbbbbbbb-bbbb-4000-b000-000000000001')

u1 > u2  -- false
u1 >= u2 -- false
u1 <= u2 -- true
u1 < u2  -- true

-- Comparison with string uuid representation supported as well

u1 > 'bbbbbbbb-bbbb-4000-b000-000000000001' -- false
u1 < 'bbbbbbbb-bbbb-4000-b000-000000000001' -- true
u1 < 'not-uuid-string' -- error

```
---
Issue: https://github.com/tarantool/tarantool/issues/5511
Branch: https://github.com/tarantool/tarantool/tree/olegrok/5511-uuid-cmp

@Changelog:
  - Allow to compare uuid values (gh-5511)

 src/exports.h          |  1 +
 src/lua/uuid.lua       | 31 +++++++++++++
 test/app/uuid.result   | 98 ++++++++++++++++++++++++++++++++++++++++++
 test/app/uuid.test.lua | 35 +++++++++++++++
 4 files changed, 165 insertions(+)

diff --git a/src/exports.h b/src/exports.h
index 867a027dc..ffbb84e3b 100644
--- a/src/exports.h
+++ b/src/exports.h
@@ -508,6 +508,7 @@ EXPORT(tnt_iconv_close)
 EXPORT(tnt_iconv_open)
 EXPORT(tt_uuid_bswap)
 EXPORT(tt_uuid_create)
+EXPORT(tt_uuid_compare)
 EXPORT(tt_uuid_from_string)
 EXPORT(tt_uuid_is_equal)
 EXPORT(tt_uuid_is_nil)
diff --git a/src/lua/uuid.lua b/src/lua/uuid.lua
index 42016601d..0ab937877 100644
--- a/src/lua/uuid.lua
+++ b/src/lua/uuid.lua
@@ -19,6 +19,8 @@ bool
 tt_uuid_is_equal(const struct tt_uuid *lhs, const struct tt_uuid *rhs);
 char *
 tt_uuid_str(const struct tt_uuid *uu);
+int
+tt_uuid_compare(const struct tt_uuid *a, const struct tt_uuid *b);
 extern const struct tt_uuid uuid_nil;
 ]]
 
@@ -118,9 +120,38 @@ local uuid_new_str = function()
     return uuid_tostring(uuidbuf)
 end
 
+local check_uuid = function(value, index)
+    if is_uuid(value) then
+        return value
+    end
+
+    if type(value) == 'string' then
+        value = uuid_fromstr(value)
+        if value ~= nil then
+            return value
+        end
+    end
+
+    error(('incorrect value to convert to uuid as %d argument'):format(index), 0)
+end
+
+local uuid_cmp = function(lhs, rhs)
+    lhs = check_uuid(lhs, 1)
+    rhs = check_uuid(rhs, 2)
+    return builtin.tt_uuid_compare(lhs, rhs)
+end
+local uuid_lt = function(lhs, rhs)
+    return uuid_cmp(lhs, rhs) < 0
+end
+local uuid_le = function(lhs, rhs)
+    return uuid_cmp(lhs, rhs) <= 0
+end
+
 local uuid_mt = {
     __tostring = uuid_tostring;
     __eq = uuid_eq;
+    __lt = uuid_lt;
+    __le = uuid_le;
     __index = {
         isnil = uuid_isnil;
         bin   = uuid_tobin;    -- binary host byteorder
diff --git a/test/app/uuid.result b/test/app/uuid.result
index 9fe0e7fb4..36388aed3 100644
--- a/test/app/uuid.result
+++ b/test/app/uuid.result
@@ -291,6 +291,104 @@ uuid.is_uuid(require('decimal').new('123'))
 ---
 - false
 ...
+--
+-- gh-5511: allow to compare uuid values
+--
+u1 = uuid.fromstr('aaaaaaaa-aaaa-4000-b000-000000000001')
+---
+...
+u2_str = 'bbbbbbbb-bbbb-4000-b000-000000000001'
+---
+...
+u2 = uuid.fromstr(u2_str)
+---
+...
+u1 > u1
+---
+- false
+...
+u1 >= u1
+---
+- true
+...
+u1 <= u1
+---
+- true
+...
+u1 < u1
+---
+- false
+...
+u1 > u2
+---
+- false
+...
+u1 >= u2
+---
+- false
+...
+u1 <= u2
+---
+- true
+...
+u1 < u2
+---
+- true
+...
+u1 > u2_str
+---
+- false
+...
+u1 >= u2_str
+---
+- false
+...
+u1 <= u2_str
+---
+- true
+...
+u1 < u2_str
+---
+- true
+...
+u1 < 1
+---
+- error: incorrect value to convert to uuid as 2 argument
+...
+u1 <= 1
+---
+- error: incorrect value to convert to uuid as 2 argument
+...
+u1 < 'abc'
+---
+- error: incorrect value to convert to uuid as 2 argument
+...
+u1 <= 'abc'
+---
+- error: incorrect value to convert to uuid as 2 argument
+...
+1 < u1
+---
+- error: incorrect value to convert to uuid as 1 argument
+...
+1 <= u1
+---
+- error: incorrect value to convert to uuid as 1 argument
+...
+'abc' < u1
+---
+- error: incorrect value to convert to uuid as 1 argument
+...
+'abc' <= u1
+---
+- error: incorrect value to convert to uuid as 1 argument
+...
+u1 = nil
+---
+...
+u2 = nil
+---
+...
 uuid = nil
 ---
 ...
diff --git a/test/app/uuid.test.lua b/test/app/uuid.test.lua
index 47a96f3c6..5a57976e1 100644
--- a/test/app/uuid.test.lua
+++ b/test/app/uuid.test.lua
@@ -108,6 +108,41 @@ uuid.is_uuid(uuid.new():str())
 uuid.is_uuid(1)
 uuid.is_uuid(require('decimal').new('123'))
 
+--
+-- gh-5511: allow to compare uuid values
+--
+
+u1 = uuid.fromstr('aaaaaaaa-aaaa-4000-b000-000000000001')
+u2_str = 'bbbbbbbb-bbbb-4000-b000-000000000001'
+u2 = uuid.fromstr(u2_str)
+
+u1 > u1
+u1 >= u1
+u1 <= u1
+u1 < u1
+
+u1 > u2
+u1 >= u2
+u1 <= u2
+u1 < u2
+
+u1 > u2_str
+u1 >= u2_str
+u1 <= u2_str
+u1 < u2_str
+
+u1 < 1
+u1 <= 1
+u1 < 'abc'
+u1 <= 'abc'
+1 < u1
+1 <= u1
+'abc' < u1
+'abc' <= u1
+
+u1 = nil
+u2 = nil
+
 uuid = nil
 
 test_run:cmd("clear filter")
-- 
2.29.0