haven/nexgb/xgbgen/go_request_reply.go

270 lines
7.4 KiB
Go

package main
import (
"fmt"
"sort"
"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.Doc.Description != "" {
c.PutComment(r.Doc.Description)
c.Putln("//")
}
allErrors := make([]string, 0, len(r.Doc.Errors))
for kind := range r.Doc.Errors {
allErrors = append(allErrors, kind)
}
sort.Strings(allErrors)
undocErrors := make([]string, 0)
for _, kind := range allErrors {
if desc := r.Doc.Errors[kind]; desc == "" {
undocErrors = append(undocErrors, kind)
} else {
c.PutComment(fmt.Sprintf("May return a %s error if %s%s", kind,
strings.ToLower(desc[:1]), desc[1:]))
c.Putln("//")
}
}
if len(undocErrors) > 0 {
c.Putln("// May return %s errors.", strings.Join(undocErrors, ", "))
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())
r.CheckExt(c)
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())
r.CheckExt(c)
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())
r.CheckExt(c)
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())
r.CheckExt(c)
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) CheckExt(c *Context) {
if !c.protocol.isExt() {
return
}
c.Putln("c.ExtLock.RLock()")
c.Putln("defer c.ExtLock.RUnlock()")
c.Putln("if _, ok := c.Extensions[\"%s\"]; !ok {", c.protocol.ExtXName)
c.Putln("panic(\"Cannot issue request '%s' using the uninitialized "+
"extension '%s'. %s.Init(connObj) must be called first.\")",
r.SrcName(), c.protocol.ExtXName, c.protocol.PkgName())
c.Putln("}")
}
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) {
sz := r.Size(c)
writeSize1 := func() {
if sz.exact {
c.Putln("xgb.Put16(buf[b:], uint16(size / 4)) " +
"// write request size in 4-byte units")
} else {
c.Putln("blen := b")
}
c.Putln("b += 2")
c.Putln("")
}
writeSize2 := func() {
if sz.exact {
c.Putln("return buf")
return
}
c.Putln("b = xgb.Pad(b)")
c.Putln("xgb.Put16(buf[blen:], uint16(b / 4)) " +
"// write request size in 4-byte units")
c.Putln("return buf[:b]")
}
c.Putln("// %s writes a %s request to a byte slice for transfer.",
r.ReqName(), r.SrcName())
c.Putln("func %s(c *xgb.Conn, %s) []byte {",
r.ReqName(), r.ParamNameTypes())
c.Putln("size := %s", sz)
c.Putln("b := 0")
c.Putln("buf := make([]byte, size)")
c.Putln("")
if c.protocol.isExt() {
c.Putln("c.ExtLock.RLock()")
c.Putln("buf[b] = c.Extensions[\"%s\"]", c.protocol.ExtXName)
c.Putln("c.ExtLock.RUnlock()")
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")
}
writeSize1()
} else if c.protocol.isExt() {
writeSize1()
}
for i, field := range r.Fields {
field.Write(c, "")
c.Putln("")
if i == 0 && !c.protocol.isExt() {
writeSize1()
}
}
writeSize2()
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:
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:
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
case *RequiredStartAlign:
continue
default:
nameTypes = append(nameTypes,
fmt.Sprintf("%s %s", field.SrcName(), field.SrcType()))
}
}
return strings.Join(nameTypes, ", ")
}