added request body reader

internal/html/html.go

@@ -0,0 +1,104 @@
+package html
+
+import (
+	"os"
+	"path"
+	"serveg/internal/http"
+	"serveg/internal/log"
+	sh "serveg/internal/string_helper"
+)
+
+type listingRow struct {
+	name  string // html-escaped
+	url   string // url-encoded
+	mtime string // formatted with DateTimeTZ
+	size  string // formatted with HumanBytes
+	isDir bool
+}
+
+func (row *listingRow) genHtml(sb *sh.StringBuilder) {
+	sb.AddS(`<tr>`)
+	sb.AddS(`<td><a href="`).AddS(row.url).AddB('"')
+	if !row.isDir {
+		// tell browser to download file instead of opening in new tab
+		sb.AddS(" download")
+	}
+	sb.AddB('>').AddS(row.name).AddS(`</a></td>`)
+	sb.AddS(`<td class="size">`).AddS(row.size).AddS(`</td>`)
+	sb.AddS(`<td class="date">`).AddS(row.mtime).AddS(`</td>`)
+	sb.AddS(`</tr>`)
+}
+
+func GenDirListingHtml(logger *log.LoggerContext, dirPath, reqUrl, pageTitle string) ([]byte, error) {
+	dirEntries, err := os.ReadDir(dirPath)
+	if err != nil {
+		return nil, err
+	}
+
+	var dirs, files []listingRow
+	var estimatedLen = 460 // html for page without entries
+	for _, e := range dirEntries {
+		einf, err := e.Info()
+		if err != nil {
+			return nil, err
+		}
+
+		row := listingRow{
+			name:  htmlEscape(e.Name()),
+			url:   http.PercentEcodeUrl(path.Join(reqUrl, e.Name())),
+			mtime: einf.ModTime().Format(DateTimeTZ),
+			isDir: e.IsDir(),
+		}
+		if row.isDir {
+			row.size = "DIR"
+			dirs = append(dirs, row)
+		} else {
+			row.size = sh.HumanBytes(einf.Size())
+			files = append(files, row)
+		}
+
+		estimatedLen += len(row.name) + len(row.url) + len(row.mtime) + len(row.size)
+		estimatedLen += 100 // html for row
+	}
+
+	sb := sh.StringBuilder{Buf: make([]byte, 0, estimatedLen)}
+	sb.AddS(`<!doctype html>
+<html>
+<head>
+<meta charset="utf-8">
+<title>`)
+	sb.AddS(htmlEscape(pageTitle + " " + reqUrl))
+	sb.AddS(`
+</title>
+<style>
+	body { font-family: sans-serif; margin: 2em; }
+	td { padding: .2em 1em .2em 0; }
+	td.size, td.date { color: #666; white-space: nowrap; }
+</style>
+</head>
+<body>`)
+	sb.AddS("<h1>").AddS(htmlEscape(reqUrl)).AddS("</h1>")
+	sb.AddS(`<table id="listing">`)
+	sb.AddS(`<tr><td><a href="`)
+	sb.AddS(http.PercentEcodeUrl(path.Dir(reqUrl)))
+	sb.AddS(`">../</a></td></tr>`)
+
+	for i := 0; i < len(dirs); i++ {
+		dirs[i].genHtml(&sb)
+	}
+	for i := 0; i < len(files); i++ {
+		files[i].genHtml(&sb)
+	}
+
+	sb.AddS(`
+</table>
+</body>
+</html>`)
+
+	realLen := sb.Len()
+	if estimatedLen < realLen {
+		logger.Warn("genDirListingHtml(): size prediction failed. estimatedLen: ",
+			estimatedLen, " realLen: ", realLen)
+	}
+	return sb.Buf, nil
+}