goprotobuf: Encode fields in proto tag order.
Fixes #20.
R=r
CC=golang-dev
http://codereview.appspot.com/5158047
diff --git a/proto/all_test.go b/proto/all_test.go
index ae419aa..36cd337 100644
--- a/proto/all_test.go
+++ b/proto/all_test.go
@@ -518,12 +518,12 @@
"8d0100004a45"+ // field 17, encoding 5, value 3232.0
"9101000000000040b940"+ // field 18, encoding 1, value 6464.0
"9a0106"+"737472696e67"+ // field 19, encoding 2, string "string"
- "aa0605"+"6279746573"+ // field 101, encoding 2, string "bytes"
- "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
- "b8067f"+ // field 103, encoding 0, 0x7f zigzag64
"b304"+ // field 70, encoding 3, start group
"ba0408"+"7265717569726564"+ // field 71, encoding 2, string "required"
- "b404") // field 70, encoding 4, end group
+ "b404"+ // field 70, encoding 4, end group
+ "aa0605"+"6279746573"+ // field 101, encoding 2, string "bytes"
+ "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
+ "b8067f") // field 103, encoding 0, 0x7f zigzag64
}
// All required fields set, defaults provided.
@@ -542,9 +542,6 @@
"8d0100004a45"+ // field 17, encoding 5, value 3232.0
"9101000000000040b940"+ // field 18, encoding 1, value 6464.0
"9a0106"+"737472696e67"+ // field 19, encoding 2 string "string"
- "aa0605"+"6279746573"+ // field 101, encoding 2 string "bytes"
- "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
- "b8067f"+ // field 103, encoding 0, 0x7f zigzag64
"c00201"+ // field 40, encoding 0, value 1
"c80220"+ // field 41, encoding 0, value 32
"d00240"+ // field 42, encoding 0, value 64
@@ -555,12 +552,15 @@
"fd02e0659948"+ // field 47, encoding 5, value 314159.0
"81030000000050971041"+ // field 48, encoding 1, value 271828.0
"8a0310"+"68656c6c6f2c2022776f726c6421220a"+ // field 49, encoding 2 string "hello, \"world!\"\n"
- "8a1907"+"4269676e6f7365"+ // field 401, encoding 2, string "Bignose"
- "90193f"+ // field 402, encoding 0, value 63
- "98197f"+ // field 403, encoding 0, value 127
"b304"+ // start group field 70 level 1
"ba0408"+"7265717569726564"+ // field 71, encoding 2, string "required"
- "b404") // end group field 70 level 1
+ "b404"+ // end group field 70 level 1
+ "aa0605"+"6279746573"+ // field 101, encoding 2 string "bytes"
+ "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
+ "b8067f"+ // field 103, encoding 0, 0x7f zigzag64
+ "8a1907"+"4269676e6f7365"+ // field 401, encoding 2, string "Bignose"
+ "90193f"+ // field 402, encoding 0, value 63
+ "98197f") // field 403, encoding 0, value 127
}
@@ -594,9 +594,6 @@
"8d0100004a45"+ // field 17, encoding 5, value 3232.0
"9101000000000040b940"+ // field 18, encoding 1, value 6464.0
"9a0106"+"737472696e67"+ // field 19, encoding 2 string "string"
- "aa0605"+"6279746573"+ // field 101, encoding 2 string "bytes"
- "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
- "b8067f"+ // field 103, encoding 0, 0x7f zigzag64
"c00201"+ // field 40, encoding 0, value 1
"c80220"+ // field 41, encoding 0, value 32
"d00240"+ // field 42, encoding 0, value 64
@@ -607,12 +604,15 @@
"fd02e0659948"+ // field 47, encoding 5, value 314159.0
"81030000000050971041"+ // field 48, encoding 1, value 271828.0
"8a0310"+"68656c6c6f2c2022776f726c6421220a"+ // field 49, encoding 2 string "hello, \"world!\"\n"
- "8a1907"+"4269676e6f7365"+ // field 401, encoding 2, string "Bignose"
- "90193f"+ // field 402, encoding 0, value 63
- "98197f"+ // field 403, encoding 0, value 127
"b304"+ // start group field 70 level 1
"ba0408"+"7265717569726564"+ // field 71, encoding 2, string "required"
- "b404") // end group field 70 level 1
+ "b404"+ // end group field 70 level 1
+ "aa0605"+"6279746573"+ // field 101, encoding 2 string "bytes"
+ "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
+ "b8067f"+ // field 103, encoding 0, 0x7f zigzag64
+ "8a1907"+"4269676e6f7365"+ // field 401, encoding 2, string "Bignose"
+ "90193f"+ // field 402, encoding 0, value 63
+ "98197f") // field 403, encoding 0, value 127
}
@@ -653,9 +653,6 @@
"8d0100004a45"+ // field 17, encoding 5, value 3232.0
"9101000000000040b940"+ // field 18, encoding 1, value 6464.0
"9a0106"+"737472696e67"+ // field 19, encoding 2 string "string"
- "aa0605"+"6279746573"+ // field 101, encoding 2 string "bytes"
- "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
- "b8067f"+ // field 103, encoding 0, 0x7f zigzag64
"f00101"+ // field 30, encoding 0, value 1
"f80120"+ // field 31, encoding 0, value 32
"800240"+ // field 32, encoding 0, value 64
@@ -666,9 +663,6 @@
"ad0200000042"+ // field 37, encoding 5, value 32.0
"b1020000000000005040"+ // field 38, encoding 1, value 64.0
"ba0205"+"68656c6c6f"+ // field 39, encoding 2, string "hello"
- "ea1207"+"4269676e6f7365"+ // field 301, encoding 2, string "Bignose"
- "f0123f"+ // field 302, encoding 0, value 63
- "f8127f"+ // field 303, encoding 0, value 127
"c00201"+ // field 40, encoding 0, value 1
"c80220"+ // field 41, encoding 0, value 32
"d00240"+ // field 42, encoding 0, value 64
@@ -679,15 +673,21 @@
"fd02e0659948"+ // field 47, encoding 5, value 314159.0
"81030000000050971041"+ // field 48, encoding 1, value 271828.0
"8a0310"+"68656c6c6f2c2022776f726c6421220a"+ // field 49, encoding 2 string "hello, \"world!\"\n"
- "8a1907"+"4269676e6f7365"+ // field 401, encoding 2, string "Bignose"
- "90193f"+ // field 402, encoding 0, value 63
- "98197f"+ // field 403, encoding 0, value 127
"b304"+ // start group field 70 level 1
"ba0408"+"7265717569726564"+ // field 71, encoding 2, string "required"
"b404"+ // end group field 70 level 1
"d305"+ // start group field 90 level 1
"da0508"+"6f7074696f6e616c"+ // field 91, encoding 2, string "optional"
- "d405") // end group field 90 level 1
+ "d405"+ // end group field 90 level 1
+ "aa0605"+"6279746573"+ // field 101, encoding 2 string "bytes"
+ "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
+ "b8067f"+ // field 103, encoding 0, 0x7f zigzag64
+ "ea1207"+"4269676e6f7365"+ // field 301, encoding 2, string "Bignose"
+ "f0123f"+ // field 302, encoding 0, value 63
+ "f8127f"+ // field 303, encoding 0, value 127
+ "8a1907"+"4269676e6f7365"+ // field 401, encoding 2, string "Bignose"
+ "90193f"+ // field 402, encoding 0, value 63
+ "98197f") // field 403, encoding 0, value 127
}
@@ -725,9 +725,6 @@
"8d0100004a45"+ // field 17, encoding 5, value 3232.0
"9101000000000040b940"+ // field 18, encoding 1, value 6464.0
"9a0106"+"737472696e67"+ // field 19, encoding 2 string "string"
- "aa0605"+"6279746573"+ // field 101, encoding 2 string "bytes"
- "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
- "b8067f"+ // field 103, encoding 0, 0x7f zigzag64
"a00100"+ // field 20, encoding 0, value 0
"a00101"+ // field 20, encoding 0, value 1
"a80120"+ // field 21, encoding 0, value 32
@@ -748,12 +745,6 @@
"e1010000000000405040"+ // field 28, encoding 1, value 65.0
"ea0105"+"68656c6c6f"+ // field 29, encoding 2, string "hello"
"ea0106"+"7361696c6f72"+ // field 29, encoding 2, string "sailor"
- "ca0c03"+"626967"+ // field 201, encoding 2, string "big"
- "ca0c04"+"6e6f7365"+ // field 201, encoding 2, string "nose"
- "d00c40"+ // field 202, encoding 0, value 32
- "d00c3f"+ // field 202, encoding 0, value -32
- "d80c8001"+ // field 203, encoding 0, value 64
- "d80c7f"+ // field 203, encoding 0, value -64
"c00201"+ // field 40, encoding 0, value 1
"c80220"+ // field 41, encoding 0, value 32
"d00240"+ // field 42, encoding 0, value 64
@@ -764,9 +755,6 @@
"fd02e0659948"+ // field 47, encoding 5, value 314159.0
"81030000000050971041"+ // field 48, encoding 1, value 271828.0
"8a0310"+"68656c6c6f2c2022776f726c6421220a"+ // field 49, encoding 2 string "hello, \"world!\"\n"
- "8a1907"+"4269676e6f7365"+ // field 401, encoding 2, string "Bignose"
- "90193f"+ // field 402, encoding 0, value 63
- "98197f"+ // field 403, encoding 0, value 127
"b304"+ // start group field 70 level 1
"ba0408"+"7265717569726564"+ // field 71, encoding 2, string "required"
"b404"+ // end group field 70 level 1
@@ -775,7 +763,19 @@
"8405"+ // end group field 80 level 1
"8305"+ // start group field 80 level 1
"8a0508"+"7265706561746564"+ // field 81, encoding 2, string "repeated"
- "8405") // end group field 80 level 1
+ "8405"+ // end group field 80 level 1
+ "aa0605"+"6279746573"+ // field 101, encoding 2 string "bytes"
+ "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
+ "b8067f"+ // field 103, encoding 0, 0x7f zigzag64
+ "ca0c03"+"626967"+ // field 201, encoding 2, string "big"
+ "ca0c04"+"6e6f7365"+ // field 201, encoding 2, string "nose"
+ "d00c40"+ // field 202, encoding 0, value 32
+ "d00c3f"+ // field 202, encoding 0, value -32
+ "d80c8001"+ // field 203, encoding 0, value 64
+ "d80c7f"+ // field 203, encoding 0, value -64
+ "8a1907"+"4269676e6f7365"+ // field 401, encoding 2, string "Bignose"
+ "90193f"+ // field 402, encoding 0, value 63
+ "98197f") // field 403, encoding 0, value 127
}
@@ -807,9 +807,6 @@
"8d0100004a45"+ // field 17, encoding 5, value 3232.0
"9101000000000040b940"+ // field 18, encoding 1, value 6464.0
"9a0106"+"737472696e67"+ // field 19, encoding 2 string "string"
- "aa0605"+"6279746573"+ // field 101, encoding 2 string "bytes"
- "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
- "b8067f"+ // field 103, encoding 0, 0x7f zigzag64
"9203020001"+ // field 50, encoding 2, 2 bytes, value 0, value 1
"9a03022021"+ // field 51, encoding 2, 2 bytes, value 32, value 33
"a203024041"+ // field 52, encoding 2, 2 bytes, value 64, value 65
@@ -825,13 +822,16 @@
"0000004200000442"+ // value 32.0, value 33.0
"d20310"+ // field 58, encoding 2, 16 bytes
"00000000000050400000000000405040"+ // value 64.0, value 65.0
+ "b304"+ // start group field 70 level 1
+ "ba0408"+"7265717569726564"+ // field 71, encoding 2, string "required"
+ "b404"+ // end group field 70 level 1
+ "aa0605"+"6279746573"+ // field 101, encoding 2 string "bytes"
+ "b0063f"+ // field 102, encoding 0, 0x3f zigzag32
+ "b8067f"+ // field 103, encoding 0, 0x7f zigzag64
"b21f02"+ // field 502, encoding 2, 2 bytes
"403f"+ // value 32, value -32
"ba1f03"+ // field 503, encoding 2, 3 bytes
- "80017f"+ // value 64, value -64
- "b304"+ // start group field 70 level 1
- "ba0408"+"7265717569726564"+ // field 71, encoding 2, string "required"
- "b404") // end group field 70 level 1
+ "80017f") // value 64, value -64
}
// Test that we can encode empty bytes fields.
diff --git a/proto/encode.go b/proto/encode.go
index 7060520..e2141c0 100644
--- a/proto/encode.go
+++ b/proto/encode.go
@@ -577,7 +577,11 @@
func (o *Buffer) enc_struct(t reflect.Type, base uintptr) os.Error {
prop := GetProperties(t)
required := prop.reqCount
- for _, p := range prop.Prop {
+ // Encode fields in tag order so that decoders may use optimizations
+ // that depend on the ordering.
+ // http://code.google.com/apis/protocolbuffers/docs/encoding.html#order
+ for _, i := range prop.order {
+ p := prop.Prop[i]
if p.enc != nil {
err := p.enc(o, p, base)
if err != nil {
diff --git a/proto/properties.go b/proto/properties.go
index 387a275..b64481d 100644
--- a/proto/properties.go
+++ b/proto/properties.go
@@ -39,6 +39,7 @@
"fmt"
"os"
"reflect"
+ "sort"
"strconv"
"strings"
"sync"
@@ -81,9 +82,19 @@
reqCount int // required count
tags map[int]int // map from proto tag to struct field number
origNames map[string]int // map from original name to struct field number
+ order []int // list of struct field numbers in tag order
nscratch uintptr // size of scratch space
}
+// Implement the sorting interface so we can sort the fields in tag order, as recommended by the spec.
+// See encoder.go, (*Buffer).enc_struct.
+
+func (sp *StructProperties) Len() int { return len(sp.order) }
+func (sp *StructProperties) Less(i, j int) bool {
+ return sp.Prop[sp.order[i]].Tag < sp.Prop[sp.order[j]].Tag
+}
+func (sp *StructProperties) Swap(i, j int) { sp.order[i], sp.order[j] = sp.order[j], sp.order[i] }
+
// Properties represents the protocol-specific behavior of a single struct field.
type Properties struct {
Name string // name of the field, for error messages
@@ -444,7 +455,7 @@
// build properties
prop.Prop = make([]*Properties, t.NumField())
- prop.origNames = make(map[string]int)
+ prop.order = make([]int, t.NumField())
for i := 0; i < t.NumField(); i++ {
f := t.Field(i)
p := new(Properties)
@@ -457,7 +468,7 @@
p.sizeof = unsafe.Sizeof(vmap)
}
prop.Prop[i] = p
- prop.origNames[p.OrigName] = i
+ prop.order[i] = i
if debug {
print(i, " ", f.Name, " ", t.String(), " ")
if p.Tag > 0 {
@@ -470,12 +481,16 @@
}
}
+ // Re-order prop.order.
+ sort.Sort(prop)
+
// build required counts
// build scratch offsets
// build tags
reqCount := 0
scratch := uintptr(0)
prop.tags = make(map[int]int)
+ prop.origNames = make(map[string]int)
for i, p := range prop.Prop {
if p.Required {
reqCount++
@@ -484,6 +499,7 @@
p.scratch = scratch
scratch += p.sizeof
prop.tags[p.Tag] = i
+ prop.origNames[p.OrigName] = i
}
prop.reqCount = reqCount
prop.nscratch = scratch