haven/nexgb/xgbgen/go_request_reply.go

214 lines
6.1 KiB
Go

package main
import (
"fmt"
"strings"
)
func (r *Request) Define(c *Context) {
c.Putln("// %s is a cookie used only for %s requests.",
r.CookieName(), r.SrcName())
c.Putln("type %s struct {", r.CookieName())
c.Putln("*xgb.Cookie")
c.Putln("}")
c.Putln("")
if r.Reply != nil {
c.Putln("// %s sends a checked request.", r.SrcName())
c.Putln("// If an error occurs, it will be returned with the reply "+
"by calling %s.Reply()", r.CookieName())
c.Putln("func %s(c *xgb.Conn, %s) %s {",
r.SrcName(), r.ParamNameTypes(), r.CookieName())
c.Putln("cookie := c.NewCookie(true, true)")
c.Putln("c.NewRequest(%s(c, %s), cookie)", r.ReqName(), r.ParamNames())
c.Putln("return %s{cookie}", r.CookieName())
c.Putln("}")
c.Putln("")
c.Putln("// %sUnchecked sends an unchecked request.", r.SrcName())
c.Putln("// If an error occurs, it can only be retrieved using " +
"xgb.WaitForEvent or xgb.PollForEvent.")
c.Putln("func %sUnchecked(c *xgb.Conn, %s) %s {",
r.SrcName(), r.ParamNameTypes(), r.CookieName())
c.Putln("cookie := c.NewCookie(false, true)")
c.Putln("c.NewRequest(%s(c, %s), cookie)", r.ReqName(), r.ParamNames())
c.Putln("return %s{cookie}", r.CookieName())
c.Putln("}")
c.Putln("")
r.ReadReply(c)
} else {
c.Putln("// %s sends an unchecked request.", r.SrcName())
c.Putln("// If an error occurs, it can only be retrieved using " +
"xgb.WaitForEvent or xgb.PollForEvent.")
c.Putln("func %s(c *xgb.Conn, %s) %s {",
r.SrcName(), r.ParamNameTypes(), r.CookieName())
c.Putln("cookie := c.NewCookie(false, false)")
c.Putln("c.NewRequest(%s(c, %s), cookie)", r.ReqName(), r.ParamNames())
c.Putln("return %s{cookie}", r.CookieName())
c.Putln("}")
c.Putln("")
c.Putln("// %sChecked sends a checked request.", r.SrcName())
c.Putln("// If an error occurs, it can be retrieved using "+
"%s.Check()", r.CookieName())
c.Putln("func %sChecked(c *xgb.Conn, %s) %s {",
r.SrcName(), r.ParamNameTypes(), r.CookieName())
c.Putln("cookie := c.NewCookie(true, false)")
c.Putln("c.NewRequest(%s(c, %s), cookie)", r.ReqName(), r.ParamNames())
c.Putln("return %s{cookie}", r.CookieName())
c.Putln("}")
c.Putln("")
c.Putln("// Check returns an error if one occurred for checked " +
"requests that are not expecting a reply.")
c.Putln("// This cannot be called for requests expecting a reply, " +
"nor for unchecked requests.")
c.Putln("func (cook %s) Check() error {", r.CookieName())
c.Putln("return cook.Cookie.Check()")
c.Putln("}")
c.Putln("")
}
r.WriteRequest(c)
}
func (r *Request) ReadReply(c *Context) {
c.Putln("// %s represents the data returned from a %s request.",
r.ReplyTypeName(), r.SrcName())
c.Putln("type %s struct {", r.ReplyTypeName())
c.Putln("Sequence uint16 // sequence number of the request for this reply")
c.Putln("Length uint32 // number of bytes in this reply")
for _, field := range r.Reply.Fields {
field.Define(c)
}
c.Putln("}")
c.Putln("")
c.Putln("// Reply blocks and returns the reply data for a %s request.",
r.SrcName())
c.Putln("func (cook %s) Reply() (*%s, error) {",
r.CookieName(), r.ReplyTypeName())
c.Putln("buf, err := cook.Cookie.Reply()")
c.Putln("if err != nil {")
c.Putln("return nil, err")
c.Putln("}")
c.Putln("if buf == nil {")
c.Putln("return nil, nil")
c.Putln("}")
c.Putln("return %s(buf), nil", r.ReplyName())
c.Putln("}")
c.Putln("")
c.Putln("// %s reads a byte slice into a %s value.",
r.ReplyName(), r.ReplyTypeName())
c.Putln("func %s(buf []byte) *%s {",
r.ReplyName(), r.ReplyTypeName())
c.Putln("v := new(%s)", r.ReplyTypeName())
c.Putln("b := 1 // skip reply determinant")
c.Putln("")
for i, field := range r.Reply.Fields {
field.Read(c, "v.")
c.Putln("")
if i == 0 {
c.Putln("v.Sequence = xgb.Get16(buf[b:])")
c.Putln("b += 2")
c.Putln("")
c.Putln("v.Length = xgb.Get32(buf[b:]) // 4-byte units")
c.Putln("b += 4")
c.Putln("")
}
}
c.Putln("return v")
c.Putln("}")
c.Putln("")
}
func (r *Request) WriteRequest(c *Context) {
writeSize := func() {
c.Putln("xgb.Put16(buf[b:], uint16(size / 4)) " +
"// write request size in 4-byte units")
c.Putln("b += 2")
c.Putln("")
}
c.Putln("// Write request to wire for %s", r.SrcName())
c.Putln("// %s writes a %s request to a byte slice.",
r.ReqName(), r.SrcName())
c.Putln("func %s(c *xgb.Conn, %s) []byte {",
r.ReqName(), r.ParamNameTypes())
c.Putln("size := %s", r.Size(c))
c.Putln("b := 0")
c.Putln("buf := make([]byte, size)")
c.Putln("")
if c.protocol.isExt() {
c.Putln("buf[b] = c.Extensions[\"%s\"]",
strings.ToUpper(c.protocol.ExtXName))
c.Putln("b += 1")
c.Putln("")
}
c.Putln("buf[b] = %d // request opcode", r.Opcode)
c.Putln("b += 1")
c.Putln("")
if len(r.Fields) == 0 {
if !c.protocol.isExt() {
c.Putln("b += 1 // padding")
}
writeSize()
} else if c.protocol.isExt() {
writeSize()
}
for i, field := range r.Fields {
field.Write(c, "")
c.Putln("")
if i == 0 && !c.protocol.isExt() {
writeSize()
}
}
c.Putln("return buf")
c.Putln("}")
c.Putln("")
}
func (r *Request) ParamNames() string {
names := make([]string, 0, len(r.Fields))
for _, field := range r.Fields {
switch f := field.(type) {
case *ValueField:
// mofos...
if r.SrcName() != "ConfigureWindow" {
names = append(names, f.MaskName)
}
names = append(names, f.ListName)
case *PadField:
continue
case *ExprField:
continue
default:
names = append(names, fmt.Sprintf("%s", field.SrcName()))
}
}
return strings.Join(names, ", ")
}
func (r *Request) ParamNameTypes() string {
nameTypes := make([]string, 0, len(r.Fields))
for _, field := range r.Fields {
switch f := field.(type) {
case *ValueField:
// mofos...
if r.SrcName() != "ConfigureWindow" {
nameTypes = append(nameTypes,
fmt.Sprintf("%s %s", f.MaskName, f.MaskType.SrcName()))
}
nameTypes = append(nameTypes,
fmt.Sprintf("%s []uint32", f.ListName))
case *PadField:
continue
case *ExprField:
continue
default:
nameTypes = append(nameTypes,
fmt.Sprintf("%s %s", field.SrcName(), field.SrcType()))
}
}
return strings.Join(nameTypes, ", ")
}