Debian control file parser.

debian/format.go

@@ -0,0 +1,82 @@
+package debian
+
+import (
+	"bufio"
+	"errors"
+	"io"
+	"strings"
+)
+
+// Stanza or paragraph of Debian control file
+type Stanza map[string]string
+
+// Parsing errors
+var (
+	ErrMalformedStanza = errors.New("malformed stanza syntax")
+)
+
+var multilineFields = make(map[string]bool)
+
+func init() {
+	multilineFields["Description"] = true
+	multilineFields["Files"] = true
+	multilineFields["Changes"] = true
+	multilineFields["Checksums-Sha1"] = true
+	multilineFields["Checksums-Sha256"] = true
+	multilineFields["Package-List"] = true
+	multilineFields["SHA256"] = true
+	multilineFields["SHA1"] = true
+	multilineFields["MD5Sum"] = true
+}
+
+// ControlFileReader implements reading of control files stanza by stanza
+type ControlFileReader struct {
+	scanner *bufio.Scanner
+}
+
+// NewControlFileReader creates ControlFileReader, it wraps with buffering
+func NewControlFileReader(r io.Reader) *ControlFileReader {
+	return &ControlFileReader{scanner: bufio.NewScanner(bufio.NewReaderSize(r, 32768))}
+}
+
+// ReadStanza reeads one stanza from control file
+func (c *ControlFileReader) ReadStanza() (Stanza, error) {
+	stanza := make(Stanza, 32)
+	lastField := ""
+	lastFieldMultiline := false
+
+	for c.scanner.Scan() {
+		line := c.scanner.Text()
+
+		// Current stanza ends with empty line
+		if line == "" {
+			if len(stanza) > 0 {
+				return stanza, nil
+			}
+			continue
+		}
+
+		if line[0] == ' ' || line[0] == '\t' {
+			if lastFieldMultiline {
+				stanza[lastField] += line + "\n"
+			} else {
+				stanza[lastField] += strings.TrimSpace(line)
+			}
+		} else {
+			parts := strings.SplitN(line, ":", 2)
+			if len(parts) != 2 {
+				return nil, ErrMalformedStanza
+			}
+			lastField = parts[0]
+			stanza[lastField] = strings.TrimSpace(parts[1])
+			_, lastFieldMultiline = multilineFields[lastField]
+		}
+	}
+	if err := c.scanner.Err(); err != nil {
+		return nil, err
+	}
+	if len(stanza) > 0 {
+		return stanza, nil
+	}
+	return nil, nil
+}

debian/format_test.go

@@ -0,0 +1,111 @@
+package debian
+
+import (
+	"bytes"
+	. "launchpad.net/gocheck"
+)
+
+type ControlFileSuite struct {
+	reader *bytes.Buffer
+}
+
+var _ = Suite(&ControlFileSuite{})
+
+const controlFile = `Package: bti
+Binary: bti
+Version: 032-1
+Maintainer: gregor herrmann <gregoa@debian.org>
+Uploaders: tony mancill <tmancill@debian.org>
+Build-Depends: debhelper (>= 8),
+  bash-completion (>= 1:1.1-3),
+  libcurl4-nss-dev, libreadline-dev, libxml2-dev, libpcre3-dev, liboauth-dev, xsltproc, docbook-xsl, docbook-xml, dh-autoreconf
+Architecture: any
+Standards-Version: 3.9.2
+Format: 3.0 (quilt)
+Files:
+ 3d5f65778bf3f89be03c313b0024b62c 1980 bti_032-1.dsc
+ 1e0d0b693fdeebec268004ba41701baf 59773 bti_032.orig.tar.gz
+ ac1229a6d685023aeb8fcb0806324aa8 5065 bti_032-1.debian.tar.gz
+Vcs-Browser: http://svn.toastfreeware.priv.at/wsvn/ToastfreewareDebian/bti/trunk/
+Vcs-Svn: http://svn.toastfreeware.priv.at/debian/bti/trunk/
+Checksums-Sha1:
+ 3da2c5a42138c884a7d9524b9706dc56c0d6d46e 1980 bti_032-1.dsc
+ 22061e3f56074703be415d65abc9ca27ef775c6a 59773 bti_032.orig.tar.gz
+ 66ae7f56a3c1f0ebe0638d0ec0599a819d72baea 5065 bti_032-1.debian.tar.gz
+Checksums-Sha256:
+ ed6015b79693f270d0a826c695b40e4d8eb4307942cac81a98f1fda479f74215 1980 bti_032-1.dsc
+ feeabec98a89040a53283d798f7d55eb4311a854f17312a177dc45919883746a 59773 bti_032.orig.tar.gz
+ f025da42efaf57db5e71a14cb8be27eb802ad23e7ab02b7ce2252454a86ac1d9 5065 bti_032-1.debian.tar.gz
+Homepage: http://gregkh.github.com/bti/
+Package-List:
+ bti deb net extra
+Directory: pool/main/b/bti
+Priority: source
+Section: net
+
+
+Package: i3-wm
+Version: 4.2-1
+Installed-Size: 1573
+Maintainer: Michael Stapelberg <stapelberg@debian.org>
+Architecture: amd64
+Provides: x-window-manager
+Depends: libc6 (>= 2.8), libev4 (>= 1:4.04), libpcre3 (>= 8.10), libstartup-notification0 (>= 0.10), libx11-6, libxcb-icccm4 (>= 0.3.8), libxcb-keysyms1 (>= 0.3.8), libxcb-randr0 (>= 1.3), libxcb-util0 (>= 0.3.8), libxcb-xinerama0, libxcb1, libxcursor1 (>> 1.1.2), libyajl2 (>= 2.0.4), perl, x11-utils
+Recommends: xfonts-base
+Suggests: rxvt-unicode | x-terminal-emulator
+Description-en: improved dynamic tiling window manager
+ Key features of i3 are good documentation, reasonable defaults (changeable in
+ a simple configuration file) and good multi-monitor support. The user
+ interface is designed for power users and emphasizes keyboard usage. i3 uses
+ XCB for asynchronous communication with X11 and aims to be fast and
+ light-weight.
+ .
+ Please be aware i3 is primarily targeted at advanced users and developers.
+Homepage: http://i3wm.org/
+Description-md5: 2be7e62f455351435b1e055745d3e81c
+Tag: implemented-in::c, interface::x11, role::program, uitoolkit::TODO,
+ works-with::unicode, x11::window-manager
+Section: x11
+Priority: extra
+Filename: pool/main/i/i3-wm/i3-wm_4.2-1_amd64.deb
+Size: 798186
+MD5sum: 3c7dbecd76d5c271401860967563fa8c
+SHA1: 2e94f3faa5d4d617061f94076b2537d15fbff73f
+SHA256: 2894bc999b3982c4e57f100fa31e21b52e14c5f3bc7ad5345f46842fcdab0db7`
+
+func (s *ControlFileSuite) SetUpTest(c *C) {
+	s.reader = bytes.NewBufferString(controlFile)
+}
+
+func (s *ControlFileSuite) TestReadStanza(c *C) {
+	r := NewControlFileReader(s.reader)
+
+	stanza1, err := r.ReadStanza()
+	c.Assert(err, IsNil)
+
+	stanza2, err := r.ReadStanza()
+	c.Assert(err, IsNil)
+
+	stanza3, err := r.ReadStanza()
+	c.Assert(err, IsNil)
+	c.Assert(stanza3, IsNil)
+
+	c.Check(stanza1["Format"], Equals, "3.0 (quilt)")
+	c.Check(stanza1["Build-Depends"], Equals, "debhelper (>= 8),bash-completion (>= 1:1.1-3),libcurl4-nss-dev, libreadline-dev, libxml2-dev, libpcre3-dev, liboauth-dev, xsltproc, docbook-xsl, docbook-xml, dh-autoreconf")
+	c.Check(stanza1["Files"], Equals, " 3d5f65778bf3f89be03c313b0024b62c 1980 bti_032-1.dsc\n"+
+		" 1e0d0b693fdeebec268004ba41701baf 59773 bti_032.orig.tar.gz\n"+" ac1229a6d685023aeb8fcb0806324aa8 5065 bti_032-1.debian.tar.gz\n")
+	c.Check(len(stanza2), Equals, 20)
+}
+
+func (s *ControlFileSuite) BenchmarkReadStanza(c *C) {
+	for i := 0; i < c.N; i++ {
+		reader := bytes.NewBufferString(controlFile)
+		r := NewControlFileReader(reader)
+		for {
+			s, e := r.ReadStanza()
+			if s == nil && e == nil {
+				break
+			}
+		}
+	}
+}