improve bytes

2 files changed, 24 insertions, 13 deletions

diff --git a/tests/modules/process/sched_process_pipe.lua b/tests/modules/process/sched_process_pipe.lua
index d3690d619..deb350372 100644
--- a/tests/modules/process/sched_process_pipe.lua
+++ b/tests/modules/process/sched_process_pipe.lua
@@ -4,34 +4,32 @@ import("core.base.scheduler")
 
 function _session_read_pipe(id, rpipeopt)
     local results = {}
-    local pipe = rpipeopt.pipe
-    print("%s/%d: read ..", pipe, id)
+    local rpipe = rpipeopt.rpipe
+    print("%s/%d: read ..", rpipe, id)
     while not rpipeopt.stop do
-        local real, data = pipe:read(8192)
+        local real, data = rpipe:read(8192)
         if real > 0 then
             table.insert(results, bytes(data, 1, real))
         elseif real == 0 then
-            if pipe:wait(pipe.EV_READ, -1) < 0 then
+            if rpipe:wait(pipe.EV_READ, -1) < 0 then
                 break
             end
         else
             break
         end
     end
-    if #results > 0 then
-        results = bytes(results)
-    end
-    print("%s/%d: read ok, size: %d", pipe, id, results:size())
+    results = bytes(results)
+    print("%s/%d: read ok, size: %d", rpipe, id, results:size())
     if results:size() > 0 then
         results:dump()
     end
-    pipe:close()
+    rpipe:close()
 end
 
 function _session(id, program, ...)
     local rpipe, wpipe = pipe.openpair(10)
-    local rpipeopt = {pipe = rpipe, stop = false}
-    scheduler.co_start(_session_read_pipe, i, rpipeopt)
+    local rpipeopt = {rpipe = rpipe, stop = false}
+    scheduler.co_start(_session_read_pipe, id, rpipeopt)
     local proc = process.openv(program, table.pack(...), {stdout = wpipe})
     local ok, status = proc:wait(-1)
     rpipeopt.stop = true
diff --git a/xmake/core/base/bytes.lua b/xmake/core/base/bytes.lua
index d1d6d8e36..6cf9747fe 100644
--- a/xmake/core/base/bytes.lua
+++ b/xmake/core/base/bytes.lua
@@ -44,6 +44,7 @@ ffi.cdef[[
 -- bytes(bytes1, bytes2, bytes3, ...): allocates and concat buffer from list of byte buffers
 -- bytes(bytes): allocates a buffer from another one (strict replica, sharing memory)
 -- bytes({bytes1, bytes2, ...}): allocates and concat buffer from a list of byte buffers (table)
+-- bytes({})/bytes(): allocate an empty buffer
 --
 function _instance.new(...)
     local args = {...}
@@ -134,7 +135,7 @@ function _instance.new(...)
             end
             instance._MANAGED  = true
             instance._READONLY = false
-        elseif not arg2 and arg1:size() then
+        elseif not arg2 and arg1.size and arg1:size() > 0 then
             -- bytes(bytes): allocates a buffer from another one (strict replica, sharing memory)
             local b = arg1
             local start = 1
@@ -147,9 +148,21 @@ function _instance.new(...)
             instance._REF      = b -- keep lua ref for GC
             instance._MANAGED  = false
             instance._READONLY = b:readonly()
+        else
+            -- bytes({}): allocate an empty buffer
+            instance._SIZE     = 0
+            instance._CDATA    = nil
+            instance._MANAGED  = false
+            instance._READONLY = true
         end
+    elseif arg1 == nil then
+        -- bytes(): allocate an empty buffer
+        instance._SIZE     = 0
+        instance._CDATA    = nil
+        instance._MANAGED  = false
+        instance._READONLY = true
     end
-    if instance:cdata() == nil then
+    if instance:size() == nil then
         os.raise("invalid arguments for bytes(...)!")
     end
     setmetatable(instance, _instance)