diff options
Diffstat (limited to 'nexgb/xgbgen/request_reply.go')
-rw-r--r-- | nexgb/xgbgen/request_reply.go | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/nexgb/xgbgen/request_reply.go b/nexgb/xgbgen/request_reply.go new file mode 100644 index 0000000..5032e31 --- /dev/null +++ b/nexgb/xgbgen/request_reply.go @@ -0,0 +1,152 @@ +package main + +import ( + "fmt" + "log" + "unicode" +) + +// Request represents all XML 'request' nodes. +// If the request doesn't have a reply, Reply is nil. +type Request struct { + srcName string // The Go name of this request. + xmlName string // The XML name of this request. + Opcode int + Combine bool // Not currently used. + Fields []Field // All fields in the request. + Reply *Reply // A reply, if one exists for this request. +} + +type Requests []*Request + +func (rs Requests) Len() int { return len(rs) } +func (rs Requests) Swap(i, j int) { rs[i], rs[j] = rs[j], rs[i] } +func (rs Requests) Less(i, j int) bool { return rs[i].xmlName < rs[j].xmlName } + +// Initialize creates the proper Go source name for this request. +// It also initializes the reply if one exists, and all fields in this request. +func (r *Request) Initialize(p *Protocol) { + r.srcName = SrcName(p, r.xmlName) + if p.isExt() { + r.srcName = r.srcName + } + + if r.Reply != nil { + r.Reply.Initialize(p) + } + for _, field := range r.Fields { + field.Initialize(p) + } +} + +func (r *Request) SrcName() string { + return r.srcName +} + +func (r *Request) XmlName() string { + return r.xmlName +} + +// ReplyName gets the Go source name of the function that generates a +// reply type from a slice of bytes. +// The generated function is not currently exported. +func (r *Request) ReplyName() string { + if r.Reply == nil { + log.Panicf("Cannot call 'ReplyName' on request %s, which has no reply.", + r.SrcName()) + } + name := r.SrcName() + lower := string(unicode.ToLower(rune(name[0]))) + name[1:] + return fmt.Sprintf("%sReply", lower) +} + +// ReplyTypeName gets the Go source name of the type holding all reply data +// for this request. +func (r *Request) ReplyTypeName() string { + if r.Reply == nil { + log.Panicf("Cannot call 'ReplyName' on request %s, which has no reply.", + r.SrcName()) + } + return fmt.Sprintf("%sReply", r.SrcName()) +} + +// ReqName gets the Go source name of the function that generates a byte +// slice from a list of parameters. +// The generated function is not currently exported. +func (r *Request) ReqName() string { + name := r.SrcName() + lower := string(unicode.ToLower(rune(name[0]))) + name[1:] + return fmt.Sprintf("%sRequest", lower) +} + +// CookieName gets the Go source name of the type that holds cookies for +// this request. +func (r *Request) CookieName() string { + return fmt.Sprintf("%sCookie", r.SrcName()) +} + +// Size for Request needs a context. +// Namely, if this is an extension, we need to account for *four* bytes +// of a header (extension opcode, request opcode, and the sequence number). +// If it's a core protocol request, then we only account for *three* +// bytes of the header (remove the extension opcode). +func (r *Request) Size(c *Context) Size { + size := newFixedSize(0, true) + + // If this is a core protocol request, we squeeze in an extra byte of + // data (from the fields below) between the opcode and the size of the + // request. In an extension request, this byte is always occupied + // by the opcode of the request (while the first byte is always occupied + // by the opcode of the extension). + if !c.protocol.isExt() { + size = size.Add(newFixedSize(3, true)) + } else { + size = size.Add(newFixedSize(4, true)) + } + + for _, field := range r.Fields { + switch field := field.(type) { + case *LocalField: // local fields don't go over the wire + continue + case *SingleField: + fsz := field.Size() + if _, isstruct := field.Type.(*Struct); isstruct { + fsz.Expression = fsz.Expression.Specialize(field.SrcName()) + } + size = size.Add(fsz) + default: + size = size.Add(field.Size()) + } + } + return newExpressionSize(&Padding{ + Expr: size.Expression, + }, size.exact) +} + +// Reply encapsulates the fields associated with a 'reply' element. +type Reply struct { + Fields []Field +} + +// Size gets the number of bytes in this request's reply. +// A reply always has at least 7 bytes: +// 1 byte: A reply discriminant (first byte set to 1) +// 2 bytes: A sequence number +// 4 bytes: Number of additional bytes in 4-byte units past initial 32 bytes. +func (r *Reply) Size() Size { + size := newFixedSize(0, true) + + // Account for reply discriminant, sequence number and reply length + size = size.Add(newFixedSize(7, true)) + + for _, field := range r.Fields { + size = size.Add(field.Size()) + } + return size +} + +func (r *Reply) Initialize(p *Protocol) { + for _, field := range r.Fields { + field.Initialize(p) + } +} |