[go] net/url: speed up escape and unescape

[Gerrit Bot (Gerrit)]

Gerrit Bot has uploaded the change for review

Commit message

net/url: speed up escape and unescape

This change adds a generated 8-bit bitmask for use in functions shouldEscape and ishex.

Function shouldEscape is now inlineable. Function escape is now much faster;
function unescape is a bit faster. Here are some benchmark results (no change
to allocations):

goos: darwin
goarch: amd64
pkg: net/url
cpu: Intel(R) Core(TM) i7-6700HQ CPU @ 2.60GHz
                    │     old      │                 new                 │
                    │    sec/op    │   sec/op     vs base                │
QueryEscape/#00-8      58.38n ± 1%   35.98n ± 1%  -38.38% (p=0.000 n=20)
QueryEscape/#01-8     303.50n ± 0%   94.77n ± 0%  -68.77% (p=0.000 n=20)
QueryEscape/#02-8     202.90n ± 0%   78.66n ± 1%  -61.23% (p=0.000 n=20)
QueryEscape/#03-8      444.5n ± 0%   145.9n ± 0%  -67.17% (p=0.000 n=20)
QueryEscape/#04-8     2678.0n ± 0%   913.7n ± 0%  -65.88% (p=0.000 n=20)
PathEscape/#00-8       81.34n ± 0%   44.64n ± 1%  -45.12% (p=0.000 n=20)
PathEscape/#01-8      307.65n ± 0%   96.71n ± 1%  -68.56% (p=0.000 n=20)
PathEscape/#02-8      200.80n ± 1%   78.25n ± 0%  -61.03% (p=0.000 n=20)
PathEscape/#03-8       450.1n ± 1%   145.5n ± 0%  -67.67% (p=0.000 n=20)
PathEscape/#04-8      2663.5n ± 0%   876.5n ± 0%  -67.09% (p=0.000 n=20)
QueryUnescape/#00-8    53.32n ± 1%   51.67n ± 1%   -3.09% (p=0.000 n=20)
QueryUnescape/#01-8    161.0n ± 1%   136.2n ± 1%  -15.40% (p=0.000 n=20)
QueryUnescape/#02-8    126.1n ± 1%   118.3n ± 1%   -6.23% (p=0.000 n=20)
QueryUnescape/#03-8    294.6n ± 0%   273.1n ± 0%   -7.30% (p=0.000 n=20)
QueryUnescape/#04-8    1.511µ ± 0%   1.411µ ± 0%   -6.62% (p=0.000 n=20)
PathUnescape/#00-8     63.84n ± 1%   53.59n ± 1%  -16.05% (p=0.000 n=20)
PathUnescape/#01-8     163.6n ± 3%   137.9n ± 1%  -15.71% (p=0.000 n=20)
PathUnescape/#02-8     126.4n ± 1%   119.1n ± 1%   -5.78% (p=0.000 n=20)
PathUnescape/#03-8     294.2n ± 0%   273.3n ± 0%   -7.12% (p=0.000 n=20)
PathUnescape/#04-8     1.554µ ± 0%   1.417µ ± 0%   -8.78% (p=0.000 n=20)
geomean                277.8n        162.7n       -41.44%

This change draws heavy inspiration from CL 174998, which showed promise but stalled years ago.

Updates #17860

Change-Id: Idcbb1696608998b9e2fc91e1f2a488d8f1f6028c

GitHub-Last-Rev: 6006e68b9dd781bba86c03b4aceed3870e1e6efa

GitHub-Pull-Request: golang/go#75914

Change diff

diff --git a/src/net/url/gen_table.go b/src/net/url/gen_table.go
new file mode 100644
index 0000000..67990d1
--- /dev/null
+++ b/src/net/url/gen_table.go
@@ -0,0 +1,216 @@
+// Copyright 2025 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build ignore
+
+package main
+
+import (
+	"bytes"
+	"fmt"
+	"go/format"
+	"io"
+	"log"
+	"maps"
+	"os"
+	"slices"
+)
+
+const filename = "table.go"
+
+func main() {
+	var out bytes.Buffer
+	fmt.Fprintln(&out, "// Code generated from gen_table.go using 'go generate'; DO NOT EDIT.")
+	fmt.Fprintln(&out)
+	fmt.Fprintln(&out, "// Copyright 2025 The Go Authors. All rights reserved.")
+	fmt.Fprintln(&out, "// Use of this source code is governed by a BSD-style")
+	fmt.Fprintln(&out, "// license that can be found in the LICENSE file.")
+	fmt.Fprintln(&out)
+	fmt.Fprintln(&out, "package url")
+	fmt.Fprintln(&out)
+	generateTable(&out)
+
+	formatted, err := format.Source(out.Bytes())
+	if err != nil {
+		log.Fatal("format:", err)
+	}
+
+	err = os.WriteFile(filename, formatted, 0644)
+	if err != nil {
+		log.Fatal("WriteFile:", err)
+	}
+}
+
+func generateTable(w io.Writer) {
+	fmt.Fprintln(w, "var table = [256]encoding{")
+
+	// Sort the encodings (in decreasing order) to guarantee a stable output.
+	sortedEncs := slices.Sorted(maps.Keys(encNames))
+	slices.Reverse(sortedEncs)
+
+	for i := range 256 {
+		c := byte(i)
+		var lineBuf bytes.Buffer
+
+		// Write key to line buffer.
+		var keyFormat string
+		if '!' <= c && c <= '~' {
+			if c == '\'' || c == '\\' {
+				keyFormat = "'\\%c'"
+			} else {
+				keyFormat = "%q"
+			}
+		} else {
+			keyFormat = "%d"
+		}
+		fmt.Fprintf(&lineBuf, keyFormat, c)
+
+		lineBuf.WriteByte(':')
+
+		// Write value to line buffer.
+		blankVal := true
+		if ishex(c) {
+			// Set the hexChar bit if this char is hexadecimal.
+			lineBuf.WriteString(hexCharName)
+			blankVal = false
+		}
+		for _, enc := range sortedEncs {
+			if !shouldEscape(c, enc) {
+				if !blankVal {
+					lineBuf.WriteByte('|')
+				}
+				// Set this encoding mode's bit if this char should NOT be
+				// escaped.
+				name := encNames[enc]
+				lineBuf.WriteString(name)
+				blankVal = false
+			}
+		}
+
+		if !blankVal {
+			lineBuf.WriteString(",\n")
+			w.Write(lineBuf.Bytes())
+		}
+	}
+	fmt.Fprintln(w, "}")
+}
+
+// Keep in sync with the definition in url.go.
+type encoding uint8
+
+// Keep in sync with the definition in url.go.
+const (
+	encodePath encoding = 1 << iota
+	encodePathSegment
+	encodeHost
+	encodeZone
+	encodeUserPassword
+	encodeQueryComponent
+	encodeFragment
+
+	// hexChar is actually NOT an encoding mode, but there are only seven
+	// encoding modes. We might as well abuse the otherwise unused most
+	// significant bit in uint8 to indicate whether a character is
+	// hexadecimal.
+	hexChar
+)
+
+// Keep in sync with the definitions in url.go.
+var encNames = map[encoding]string{
+	encodePath:           "encodePath",
+	encodePathSegment:    "encodePathSegment",
+	encodeHost:           "encodeHost",
+	encodeZone:           "encodeZone",
+	encodeUserPassword:   "encodeUserPassword",
+	encodeQueryComponent: "encodeQueryComponent",
+	encodeFragment:       "encodeFragment",
+}
+
+// Keep in sync with the definition of hexChar in url.go.
+const hexCharName = "hexChar"
+
+// Return true if the specified character should be escaped when
+// appearing in a URL string, according to RFC 3986.
+//
+// Please be informed that for now shouldEscape does not check all
+// reserved characters correctly. See golang.org/issue/5684.
+func shouldEscape(c byte, mode encoding) bool {
+	// §2.3 Unreserved characters (alphanum)
+	if 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' || '0' <= c && c <= '9' {
+		return false
+	}
+	if mode == encodeHost || mode == encodeZone {
+		// §3.2.2 Host allows
+		//  sub-delims = "!" / "$" / "&" / "'" / "(" / ")" / "*" / "+" / "," / ";" / "="
+		// as part of reg-name.
+		// We add : because we include :port as part of host.
+		// We add [ ] because we include [ipv6]:port as part of host.
+		// We add < > because they're the only characters left that
+		// we could possibly allow, and Parse will reject them if we
+		// escape them (because hosts can't use %-encoding for
+		// ASCII bytes).
+		switch c {
+		case '!', '$', '&', '\'', '(', ')', '*', '+', ',', ';', '=', ':', '[', ']', '<', '>', '"':
+			return false
+		}
+	}
+	switch c {
+	case '-', '_', '.', '~': // §2.3 Unreserved characters (mark)
+		return false
+	case '$', '&', '+', ',', '/', ':', ';', '=', '?', '@': // §2.2 Reserved characters (reserved)
+		// Different sections of the URL allow a few of
+		// the reserved characters to appear unescaped.
+		switch mode {
+		case encodePath: // §3.3
+			// The RFC allows : @ & = + $ but saves / ; , for assigning
+			// meaning to individual path segments. This package
+			// only manipulates the path as a whole, so we allow those
+			// last three as well. That leaves only ? to escape.
+			return c == '?'
+		case encodePathSegment: // §3.3
+			// The RFC allows : @ & = + $ but saves / ; , for assigning
+			// meaning to individual path segments.
+			return c == '/' || c == ';' || c == ',' || c == '?'
+		case encodeUserPassword: // §3.2.1
+			// The RFC allows ';', ':', '&', '=', '+', '$', and ',' in
+			// userinfo, so we must escape only '@', '/', and '?'.
+			// The parsing of userinfo treats ':' as special so we must escape
+			// that too.
+			return c == '@' || c == '/' || c == '?' || c == ':'
+		case encodeQueryComponent: // §3.4
+			// The RFC reserves (so we must escape) everything.
+			return true
+		case encodeFragment: // §4.1
+			// The RFC text is silent but the grammar allows
+			// everything, so escape nothing.
+			return false
+		}
+	}
+	if mode == encodeFragment {
+		// RFC 3986 §2.2 allows not escaping sub-delims. A subset of sub-delims are
+		// included in reserved from RFC 2396 §2.2. The remaining sub-delims do not
+		// need to be escaped. To minimize potential breakage, we apply two restrictions:
+		// (1) we always escape sub-delims outside of the fragment, and (2) we always
+		// escape single quote to avoid breaking callers that had previously assumed that
+		// single quotes would be escaped. See issue #19917.
+		switch c {
+		case '!', '(', ')', '*':
+			return false
+		}
+	}
+	// Everything else must be escaped.
+	return true
+}
+
+func ishex(c byte) bool {
+	switch {
+	case '0' <= c && c <= '9':
+		return true
+	case 'a' <= c && c <= 'f':
+		return true
+	case 'A' <= c && c <= 'F':
+		return true
+	}
+	return false
+}
diff --git a/src/net/url/table.go b/src/net/url/table.go
new file mode 100644
index 0000000..b0be6a7
--- /dev/null
+++ b/src/net/url/table.go
@@ -0,0 +1,96 @@
+// Code generated from gen_table.go using 'go generate'; DO NOT EDIT.
+
+// Copyright 2025 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package url
+
+var table = [256]encoding{
+	'!':  encodeFragment | encodeZone | encodeHost,
+	'"':  encodeZone | encodeHost,
+	'$':  encodeFragment | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'&':  encodeFragment | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'\'': encodeZone | encodeHost,
+	'(':  encodeFragment | encodeZone | encodeHost,
+	')':  encodeFragment | encodeZone | encodeHost,
+	'*':  encodeFragment | encodeZone | encodeHost,
+	'+':  encodeFragment | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	',':  encodeFragment | encodeUserPassword | encodeZone | encodeHost | encodePath,
+	'-':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'.':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'/':  encodeFragment | encodePath,
+	'0':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'1':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'2':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'3':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'4':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'5':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'6':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'7':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'8':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'9':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	':':  encodeFragment | encodeZone | encodeHost | encodePathSegment | encodePath,
+	';':  encodeFragment | encodeUserPassword | encodeZone | encodeHost | encodePath,
+	'<':  encodeZone | encodeHost,
+	'=':  encodeFragment | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'>':  encodeZone | encodeHost,
+	'?':  encodeFragment,
+	'@':  encodeFragment | encodePathSegment | encodePath,
+	'A':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'B':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'C':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'D':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'E':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'F':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'G':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'H':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'I':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'J':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'K':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'L':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'M':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'N':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'O':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'P':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'Q':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'R':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'S':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'T':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'U':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'V':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'W':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'X':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'Y':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'Z':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'[':  encodeZone | encodeHost,
+	']':  encodeZone | encodeHost,
+	'_':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'a':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'b':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'c':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'd':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'e':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'f':  hexChar | encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'g':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'h':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'i':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'j':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'k':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'l':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'm':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'n':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'o':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'p':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'q':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'r':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	's':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	't':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'u':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'v':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'w':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'x':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'y':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'z':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+	'~':  encodeFragment | encodeQueryComponent | encodeUserPassword | encodeZone | encodeHost | encodePathSegment | encodePath,
+}
diff --git a/src/net/url/url.go b/src/net/url/url.go
index 6afa30f..d839f29 100644
--- a/src/net/url/url.go
+++ b/src/net/url/url.go
@@ -7,6 +7,9 @@
 // See RFC 3986. This package generally follows RFC 3986, except where
 // it deviates for compatibility reasons.
 // RFC 6874 followed for IPv6 zone literals.
+
+//go:generate go run gen_table.go
+
 package url
 
 // When sending changes, first  search old issues for history on decisions.
@@ -51,15 +54,7 @@
 const upperhex = "0123456789ABCDEF"
 
 func ishex(c byte) bool {
-	switch {
-	case '0' <= c && c <= '9':
-		return true
-	case 'a' <= c && c <= 'f':
-		return true
-	case 'A' <= c && c <= 'F':
-		return true
-	}
-	return false
+	return table[c]&hexChar != 0
 }
 
 func unhex(c byte) byte {
@@ -75,16 +70,17 @@
 	}
 }
 
-type encoding int
+type encoding uint8
 
 const (
-	encodePath encoding = 1 + iota
+	encodePath encoding = 1 << iota
 	encodePathSegment
 	encodeHost
 	encodeZone
 	encodeUserPassword
 	encodeQueryComponent
 	encodeFragment
+	hexChar
 )
 
 type EscapeError string
@@ -105,80 +101,7 @@
 // Please be informed that for now shouldEscape does not check all
 // reserved characters correctly. See golang.org/issue/5684.
 func shouldEscape(c byte, mode encoding) bool {
-	// §2.3 Unreserved characters (alphanum)
-	if 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z' || '0' <= c && c <= '9' {
-		return false
-	}
-
-	if mode == encodeHost || mode == encodeZone {
-		// §3.2.2 Host allows
-		//	sub-delims = "!" / "$" / "&" / "'" / "(" / ")" / "*" / "+" / "," / ";" / "="
-		// as part of reg-name.
-		// We add : because we include :port as part of host.
-		// We add [ ] because we include [ipv6]:port as part of host.
-		// We add < > because they're the only characters left that
-		// we could possibly allow, and Parse will reject them if we
-		// escape them (because hosts can't use %-encoding for
-		// ASCII bytes).
-		switch c {
-		case '!', '$', '&', '\'', '(', ')', '*', '+', ',', ';', '=', ':', '[', ']', '<', '>', '"':
-			return false
-		}
-	}
-
-	switch c {
-	case '-', '_', '.', '~': // §2.3 Unreserved characters (mark)
-		return false
-
-	case '$', '&', '+', ',', '/', ':', ';', '=', '?', '@': // §2.2 Reserved characters (reserved)
-		// Different sections of the URL allow a few of
-		// the reserved characters to appear unescaped.
-		switch mode {
-		case encodePath: // §3.3
-			// The RFC allows : @ & = + $ but saves / ; , for assigning
-			// meaning to individual path segments. This package
-			// only manipulates the path as a whole, so we allow those
-			// last three as well. That leaves only ? to escape.
-			return c == '?'
-
-		case encodePathSegment: // §3.3
-			// The RFC allows : @ & = + $ but saves / ; , for assigning
-			// meaning to individual path segments.
-			return c == '/' || c == ';' || c == ',' || c == '?'
-
-		case encodeUserPassword: // §3.2.1
-			// The RFC allows ';', ':', '&', '=', '+', '$', and ',' in
-			// userinfo, so we must escape only '@', '/', and '?'.
-			// The parsing of userinfo treats ':' as special so we must escape
-			// that too.
-			return c == '@' || c == '/' || c == '?' || c == ':'
-
-		case encodeQueryComponent: // §3.4
-			// The RFC reserves (so we must escape) everything.
-			return true
-
-		case encodeFragment: // §4.1
-			// The RFC text is silent but the grammar allows
-			// everything, so escape nothing.
-			return false
-		}
-	}
-
-	if mode == encodeFragment {
-		// RFC 3986 §2.2 allows not escaping sub-delims. A subset of sub-delims are
-		// included in reserved from RFC 2396 §2.2. The remaining sub-delims do not
-		// need to be escaped. To minimize potential breakage, we apply two restrictions:
-		// (1) we always escape sub-delims outside of the fragment, and (2) we always
-		// escape single quote to avoid breaking callers that had previously assumed that
-		// single quotes would be escaped. See issue #19917.
-		switch c {
-		case '!', '(', ')', '*':
-			return false
-		}
-	}
-
-	// Everything else must be escaped.
-	return true
+	return table[c]&mode == 0
 }
 
 // QueryUnescape does the inverse transformation of [QueryEscape],

Change information

Files:

• A src/net/url/gen_table.go
• A src/net/url/table.go
• M src/net/url/url.go

Change size: L

Delta: 3 files changed, 320 insertions(+), 85 deletions(-)

Open in Gerrit

Related details

Attention set is empty

Submit Requirements:

• Code-Review
• No-Unresolved-Comments
• Review-Enforcement
• TryBots-Pass

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

Gerrit-MessageType: newchange

Gerrit-Project: go

Gerrit-Branch: master

Gerrit-Change-Id: Idcbb1696608998b9e2fc91e1f2a488d8f1f6028c

Gerrit-Change-Number: 712200

Gerrit-PatchSet: 1

Gerrit-Owner: Gerrit Bot <letsus...@gmail.com>

Gerrit-CC: jub0bs <jub0bsin...@gmail.com>

[jub0bs (Gerrit)]

jub0bs added 1 comment

Patchset-level comments

File-level comment, Patchset 1 (Latest):

jub0bs . resolved

cc @joe...@digital-static.net

Open in Gerrit

Related details

Attention set is empty

Submit Requirements:

• Code-Review
• No-Unresolved-Comments
• Review-Enforcement
• TryBots-Pass

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

Gerrit-MessageType: comment

Gerrit-Project: go

Gerrit-Branch: master

Gerrit-Change-Id: Idcbb1696608998b9e2fc91e1f2a488d8f1f6028c

Gerrit-Change-Number: 712200

Gerrit-PatchSet: 1

Gerrit-Owner: Gerrit Bot <letsus...@gmail.com>

Gerrit-CC: Joseph Tsai <joe...@digital-static.net>

Gerrit-CC: jub0bs <jub0bsin...@gmail.com>

Gerrit-Comment-Date: Wed, 15 Oct 2025 19:30:08 +0000

Gerrit-HasComments: Yes

Gerrit-Has-Labels: No

[Sean Liao (Gerrit)]

Attention needed from jub0bs

Sean Liao added 2 comments

File src/net/url/gen_table.go

Line 67, Patchset 1 (Latest): fmt.Fprintf(&lineBuf, keyFormat, c)

Sean Liao . unresolved

use strconv QuoteRune instead of a non constant format string?

Line 100, Patchset 1 (Latest):type encoding uint8

Sean Liao . unresolved

rather than say keep in sync, can we just make this the canonical version, and part of the generated file?

you could embed the source file, strip out everything outside of some marker comments, and write to the generated file.

Open in Gerrit

Related details

Attention is currently required from:

• jub0bs

Submit Requirements:

• Code-Review

• No-Unresolved-Comments

• Review-Enforcement
• TryBots-Pass

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

Gerrit-MessageType: comment

Gerrit-Project: go

Gerrit-Branch: master

Gerrit-Change-Id: Idcbb1696608998b9e2fc91e1f2a488d8f1f6028c

Gerrit-Change-Number: 712200

Gerrit-PatchSet: 1

Gerrit-Owner: Gerrit Bot <letsus...@gmail.com>

Gerrit-CC: Joseph Tsai <joe...@digital-static.net>

Gerrit-CC: Sean Liao <se...@liao.dev>

Gerrit-CC: jub0bs <jub0bsin...@gmail.com>

Gerrit-Attention: jub0bs <jub0bsin...@gmail.com>

Gerrit-Comment-Date: Wed, 15 Oct 2025 20:14:26 +0000

Gerrit-HasComments: Yes

Gerrit-Has-Labels: No

[Gerrit Bot (Gerrit)]

Attention needed from jub0bs

Gerrit Bot uploaded new patchset

Gerrit Bot uploaded patch set #2 to this change.

Open in Gerrit

Related details

Attention is currently required from:

• jub0bs

Submit Requirements:

• Code-Review
• No-Unresolved-Comments
• Review-Enforcement
• TryBots-Pass

Inspect html for hidden footers to help with email filtering. To unsubscribe visit settings.

Gerrit

Gerrit-MessageType: newpatchset

Gerrit-Project: go

Gerrit-Branch: master

Gerrit-Change-Id: Idcbb1696608998b9e2fc91e1f2a488d8f1f6028c

Gerrit-Change-Number: 712200

Gerrit-PatchSet: 2