18051: Speed up manifest parsing with bytes.Split.

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tom@curii.com>

diff --git a/sdk/go/arvados/fs_collection.go b/sdk/go/arvados/fs_collection.go
index 4d9db421fc3838b268fdeaeea1b81b9ca1192843..647b2c405cb330e4f0b43fae24b9f89924e9d7b6 100644 (file)
--- a/sdk/go/arvados/fs_collection.go
+++ b/sdk/go/arvados/fs_collection.go
@@ -5,6 +5,7 @@
 package arvados
 
 import (
+       "bytes"
        "context"
        "encoding/json"
        "fmt"
@@ -1041,8 +1042,8 @@ func (dn *dirnode) marshalManifest(ctx context.Context, prefix string) (string,
 
 func (dn *dirnode) loadManifest(txt string) error {
        var dirname string
-       streams := strings.Split(txt, "\n")
-       if streams[len(streams)-1] != "" {
+       streams := bytes.Split([]byte(txt), []byte{'\n'})
+       if len(streams[len(streams)-1]) != 0 {
                return fmt.Errorf("line %d: no trailing newline", len(streams))
        }
        streams = streams[:len(streams)-1]
@@ -1053,25 +1054,25 @@ func (dn *dirnode) loadManifest(txt string) error {
                var pos int64
                var segIdx int
                segments = segments[:0]
-               for i, token := range strings.Split(stream, " ") {
+               for i, token := range bytes.Split(stream, []byte{' '}) {
                        if i == 0 {
-                               dirname = manifestUnescape(token)
+                               dirname = manifestUnescape(string(token))
                                continue
                        }
-                       if !strings.Contains(token, ":") {
+                       if !bytes.ContainsRune(token, ':') {
                                if anyFileTokens {
                                        return fmt.Errorf("line %d: bad file segment %q", lineno, token)
                                }
-                               toks := strings.SplitN(token, "+", 3)
+                               toks := bytes.SplitN(token, []byte{'+'}, 3)
                                if len(toks) < 2 {
                                        return fmt.Errorf("line %d: bad locator %q", lineno, token)
                                }
-                               length, err := strconv.ParseInt(toks[1], 10, 32)
+                               length, err := strconv.ParseInt(string(toks[1]), 10, 32)
                                if err != nil || length < 0 {
                                        return fmt.Errorf("line %d: bad locator %q", lineno, token)
                                }
                                segments = append(segments, storedSegment{
-                                       locator: token,
+                                       locator: string(token),
                                        size:    int(length),
                                        offset:  0,
                                        length:  int(length),
@@ -1081,21 +1082,21 @@ func (dn *dirnode) loadManifest(txt string) error {
                                return fmt.Errorf("line %d: bad locator %q", lineno, token)
                        }
 
-                       toks := strings.SplitN(token, ":", 3)
+                       toks := bytes.SplitN(token, []byte{':'}, 3)
                        if len(toks) != 3 {
                                return fmt.Errorf("line %d: bad file segment %q", lineno, token)
                        }
                        anyFileTokens = true
 
-                       offset, err := strconv.ParseInt(toks[0], 10, 64)
+                       offset, err := strconv.ParseInt(string(toks[0]), 10, 64)
                        if err != nil || offset < 0 {
                                return fmt.Errorf("line %d: bad file segment %q", lineno, token)
                        }
-                       length, err := strconv.ParseInt(toks[1], 10, 64)
+                       length, err := strconv.ParseInt(string(toks[1]), 10, 64)
                        if err != nil || length < 0 {
                                return fmt.Errorf("line %d: bad file segment %q", lineno, token)
                        }
-                       name := dirname + "/" + manifestUnescape(toks[2])
+                       name := dirname + "/" + manifestUnescape(string(toks[2]))
                        fnode, err := dn.createFileAndParents(name)
                        if fnode == nil && err == nil && length == 0 {
                                // Special case: an empty file used as