v1.11.0 - Improved the filesystem library to buffer file reading.

halyde/core/boot.lua

@@ -1,7 +1,7 @@
 local loadfile = ...
 local filesystem = loadfile("/halyde/lib/filesystem.lua")(loadfile)
 
-_G._OSVERSION = "Halyde 1.10.0"
+_G._OSVERSION = "Halyde 1.11.0"
 _G._OSLOGO = ""
 local handle, tmpdata = filesystem.open("/halyde/config/oslogo.ans", "r"), nil
 repeat

halyde/lib/filesystem.lua

@@ -69,12 +69,60 @@ function filesystem.exists(path) -- check if path exists
   return component.invoke(address, "exists", absPath)
 end
 
-function filesystem.open(path, mode) -- opens a file and returns its handle
+local function readUniChar(readByte)
+    local function inRange(min,max,...)
+        for _,v in ipairs({...}) do
+            if not (v and v>=min and v<max) then return false end
+        end
+        return true
+    end
+    local function readByte0() return readByte() or 0 end
+
+    local byte = readByte()
+
+    if byte < 0x80 then
+        -- ASCII character (0xxxxxxx)
+        return byte
+    elseif byte < 0xC0 then
+        -- Continuation byte (10xxxxxx), invalid at start position
+        return nil
+    elseif byte < 0xE0 then
+        -- 2-byte sequence (110xxxxx 10xxxxxx)
+        local byte2 = readByte0()
+        if inRange(0x80,0xC0,byte2) then
+            local code_point = ((byte & 0x1F) << 6) | (byte2 & 0x3F)
+            return code_point
+        end
+    elseif byte < 0xF0 then
+        -- 3-byte sequence (1110xxxx 10xxxxxx 10xxxxxx)
+        local byte2, byte3 = readByte0(), readByte0()
+        if inRange(0x80,0xC0,byte2,byte3)then
+            local code_point = ((byte & 0x0F) << 12) | ((byte2 & 0x3F) << 6) | (byte3 & 0x3F)
+            return code_point
+        end
+    elseif byte < 0xF8 then
+        -- 4-byte sequence (11110xxx 10xxxxxx 10xxxxxx 10xxxxxx)
+        local byte2, byte3, byte4 = readByte0(), readByte0(), readByte0()
+        if inRange(0x80,0xC0,byte2,byte3,byte4) then
+            local code_point = ((byte & 0x07) << 18) | ((byte2 & 0x3F) << 12) | ((byte3 & 0x3F) << 6) | (byte4 & 0x3F)
+            return code_point
+        end
+    end
+
+    -- Invalid UTF-8 byte sequence
+    return nil
+end
+
+function filesystem.open(path, mode, buffered) -- opens a file and returns its handle
   checkArg(1, path, "string")
   checkArg(2, mode, "string", "nil")
+  checkArg(3, buffered, "boolean", "nil")
   if not mode then
     mode = "r"
   end
+  if not buffered then
+    buffered = true
+  end
   if not (mode == "r" or mode == "w" or mode == "rb" or mode == "wb") then
     return nil, "invalid handle type"
   end
@@ -88,16 +136,62 @@ function filesystem.open(path, mode) -- opens a file and returns its handle
   local properHandle = {}
   properHandle.handle = handle
   properHandle.address = address
+  local content = nil
+  local readcursor = 1
+  if buffered and mode:sub(1,1)=="r" then
+    content=""
+    repeat
+      tmpdata = component.invoke(address, "read", handle, math.huge or math.maxinteger)
+      content = content .. (tmpdata or "")
+    until not tmpdata
+    component.invoke(address, "close", handle)
+  end
   function properHandle.read(self, amount)
     checkArg(2, amount, "number")
-    return component.invoke(self.address, "read", self.handle, amount)
+    if buffered then
+      local limit = string.len(content)+1
+      local out = nil
+      -- error("amount "..amount..", limit "..limit)
+      if readcursor<limit then
+        if amount==math.huge then
+          out = string.sub(content,math.min(readcursor,limit))
+        else
+          out = string.sub(content,math.min(readcursor,limit),math.min(readcursor+amount-1,limit))
+        end
+      end
+      readcursor=readcursor+amount
+      if out=="" then
+        return nil
+      end
+      return out
+    else
+      return component.invoke(self.address, "read", self.handle, amount)
+    end
+  end
+  function properHandle.readBytes(self,n)
+    n = n or 1
+    if n==1 then return string.byte(self:read(1)) end
+    local bytes, res = {string.byte(self:read(n),1,n)}, 0
+    for i=1,#bytes do
+      res = (res<<8)&0xFFFFFFFF | bytes[i]
+    end
+    return res
+  end
+  function properHandle.readUnicodeChar(self)
+    return unicode.char(readUniChar(function()
+      return self:readBytes(1)
+    end))
   end
   function properHandle.write(self, data)
     checkArg(2, data, "string")
     return component.invoke(self.address, "write", self.handle, data)
   end
   function properHandle.close(self)
-    return component.invoke(self.address, "close", self.handle)
+    if buffered then
+      content = nil
+    else
+      return component.invoke(self.address, "close", self.handle)
+    end
   end
   return properHandle
 end