Merge pull request #14 from Uncurlhalo/add-mime-detection

Assign extention based on mimetype if empty extension
This commit is contained in:
Andrei Marcu 2015-09-29 22:10:19 -04:00
commit f1135085c2
2 changed files with 793 additions and 2 deletions

View File

@ -1,6 +1,7 @@
package main
import (
"bytes"
"encoding/json"
"errors"
"fmt"
@ -12,6 +13,7 @@ import (
"strconv"
"strings"
"bitbucket.org/taruti/mimemagic"
"github.com/zenazn/goji/web"
)
@ -122,13 +124,29 @@ func processUpload(upReq UploadRequest) (upload Upload, err error) {
// Determine the appropriate filename, then write to disk
barename, extension := barePlusExt(upReq.filename)
// Pull the first 512 bytes off for use in MIME detection if needed
header := make([]byte, 512)
_, err = upReq.src.Read(header)
if err != nil {
return
}
if upReq.randomBarename || len(barename) == 0 {
barename = generateBarename()
}
if len(extension) == 0 {
// Determine the type of file from header
mimetype := mimemagic.Match("", header)
// If the mime type is in our map, use that
// otherwise just use "ext"
if val, exists := mimeToExtension[mimetype]; exists {
extension = val
} else {
extension = "ext"
}
}
upload.Filename = strings.Join([]string{barename, extension}, ".")
@ -166,7 +184,10 @@ func processUpload(upReq UploadRequest) (upload Upload, err error) {
metadataWrite(upload.Filename, &upload)
bytes, err := io.Copy(dst, upReq.src)
// Make a multi-reader from the header and the remainder of bytes
// in the upReq.src io.Reader
src := io.MultiReader(bytes.NewReader(header), upReq.src)
bytes, err := io.Copy(dst, src)
if err != nil {
return
} else if bytes == 0 {

770
util.go
View File

@ -8,6 +8,776 @@ import (
// from http://stackoverflow.com/a/31832326
var src = rand.NewSource(time.Now().UnixNano())
var mimeToExtension = map[string]string{
"application/andrew-inset": "ez",
"application/applixware": "aw",
"application/atom+xml": "atom",
"application/atomcat+xml": "atomcat",
"application/atomsvc+xml": "atomsvc",
"application/ccxml+xml": "ccxml",
"application/cdmi-capability": "cdmia",
"application/cdmi-container": "cdmic",
"application/cdmi-domain": "cdmid",
"application/cdmi-object": "cdmio",
"application/cdmi-queue": "cdmiq",
"application/cu-seeme": "cu",
"application/davmount+xml": "davmount",
"application/docbook+xml": "dbk",
"application/dssc+der": "dssc",
"application/dssc+xml": "xdssc",
"application/ecmascript": "ecma",
"application/emma+xml": "emma",
"application/epub+zip": "epub",
"application/exi": "exi",
"application/font-tdpfr": "pfr",
"application/gml+xml": "gml",
"application/gpx+xml": "gpx",
"application/gxf": "gxf",
"application/hyperstudio": "stk",
"application/inkml+xml": "ink inkml",
"application/ipfix": "ipfix",
"application/java-archive": "jar",
"application/java-serialized-object": "ser",
"application/java-vm": "class",
"application/javascript": "js",
"application/json": "json",
"application/jsonml+json": "jsonml",
"application/lost+xml": "lostxml",
"application/mac-binhex40": "hqx",
"application/mac-compactpro": "cpt",
"application/mads+xml": "mads",
"application/marc": "mrc",
"application/marcxml+xml": "mrcx",
"application/mathematica": "ma",
"application/mathml+xml": "mathml",
"application/mbox": "mbox",
"application/mediaservercontrol+xml": "mscml",
"application/metalink+xml": "metalink",
"application/metalink4+xml": "meta4",
"application/mets+xml": "mets",
"application/mods+xml": "mods",
"application/mp21": "mp21",
"application/mp4": "mp4s",
"application/msword": "doc",
"application/mxf": "mxf",
"application/octet-stream": "bin",
"application/oda": "oda",
"application/oebps-package+xml": "opf",
"application/ogg": "ogx",
"application/omdoc+xml": "omdoc",
"application/onenote": "onetoc",
"application/oxps": "oxps",
"application/patch-ops-error+xml": "xer",
"application/pdf": "pdf",
"application/pgp-encrypted": "pgp",
"application/pgp-signature": "asc",
"application/pics-rules": "prf",
"application/pkcs10": "p10",
"application/pkcs7-mime": "p7m",
"application/pkcs7-signature": "p7s",
"application/pkcs8": "p8",
"application/pkix-attr-cert": "ac",
"application/pkix-cert": "cer",
"application/pkix-crl": "crl",
"application/pkix-pkipath": "pkipath",
"application/pkixcmp": "pki",
"application/pls+xml": "pls",
"application/postscript": "ps",
"application/prs.cww": "cww",
"application/pskc+xml": "pskcxml",
"application/rdf+xml": "rdf",
"application/reginfo+xml": "rif",
"application/relax-ng-compact-syntax": "rnc",
"application/resource-lists+xml": "rl",
"application/resource-lists-diff+xml": "rld",
"application/rls-services+xml": "rs",
"application/rpki-ghostbusters": "gbr",
"application/rpki-manifest": "mft",
"application/rpki-roa": "roa",
"application/rsd+xml": "rsd",
"application/rss+xml": "rss",
"application/rtf": "rtf",
"application/sbml+xml": "sbml",
"application/scvp-cv-request": "scq",
"application/scvp-cv-response": "scs",
"application/scvp-vp-request": "spq",
"application/scvp-vp-response": "spp",
"application/sdp": "sdp",
"application/set-payment-initiation": "setpay",
"application/set-registration-initiation": "setreg",
"application/shf+xml": "shf",
"application/smil+xml": "smil",
"application/sparql-query": "rq",
"application/sparql-results+xml": "srx",
"application/srgs": "gram",
"application/srgs+xml": "grxml",
"application/sru+xml": "sru",
"application/ssdl+xml": "ssdl",
"application/ssml+xml": "ssml",
"application/tei+xml": "tei",
"application/thraud+xml": "tfi",
"application/timestamped-data": "tsd",
"application/vnd.3gpp.pic-bw-large": "plb",
"application/vnd.3gpp.pic-bw-small": "psb",
"application/vnd.3gpp.pic-bw-var": "pvb",
"application/vnd.3gpp2.tcap": "tcap",
"application/vnd.3m.post-it-notes": "pwn",
"application/vnd.accpac.simply.aso": "aso",
"application/vnd.accpac.simply.imp": "imp",
"application/vnd.acucobol": "acu",
"application/vnd.acucorp": "atc acutc",
"application/vnd.adobe.air-application-installer-package+zip": "air",
"application/vnd.adobe.formscentral.fcdt": "fcdt",
"application/vnd.adobe.fxp": "fxp",
"application/vnd.adobe.xdp+xml": "xdp",
"application/vnd.adobe.xfdf": "xfdf",
"application/vnd.ahead.space": "ahead",
"application/vnd.airzip.filesecure.azf": "azf",
"application/vnd.airzip.filesecure.azs": "azs",
"application/vnd.amazon.ebook": "azw",
"application/vnd.americandynamics.acc": "acc",
"application/vnd.amiga.ami": "ami",
"application/vnd.android.package-archive": "apk",
"application/vnd.anser-web-certificate-issue-initiation": "cii",
"application/vnd.anser-web-funds-transfer-initiation": "fti",
"application/vnd.antix.game-component": "atx",
"application/vnd.apple.installer+xml": "mpkg",
"application/vnd.apple.mpegurl": "m3u8",
"application/vnd.aristanetworks.swi": "swi",
"application/vnd.astraea-software.iota": "iota",
"application/vnd.audiograph": "aep",
"application/vnd.blueice.multipass": "mpm",
"application/vnd.bmi": "bmi",
"application/vnd.businessobjects": "rep",
"application/vnd.chemdraw+xml": "cdxml",
"application/vnd.chipnuts.karaoke-mmd": "mmd",
"application/vnd.cinderella": "cdy",
"application/vnd.claymore": "cla",
"application/vnd.cloanto.rp9": "rp9",
"application/vnd.clonk.c4group": "c4g",
"application/vnd.cluetrust.cartomobile-config": "c11amc",
"application/vnd.cluetrust.cartomobile-config-pkg": "c11amz",
"application/vnd.commonspace": "csp",
"application/vnd.contact.cmsg": "cdbcmsg",
"application/vnd.cosmocaller": "cmc",
"application/vnd.crick.clicker": "clkx",
"application/vnd.crick.clicker.keyboard": "clkk",
"application/vnd.crick.clicker.palette": "clkp",
"application/vnd.crick.clicker.template": "clkt",
"application/vnd.crick.clicker.wordbank": "clkw",
"application/vnd.criticaltools.wbs+xml": "wbs",
"application/vnd.ctc-posml": "pml",
"application/vnd.cups-ppd": "ppd",
"application/vnd.curl.car": "car",
"application/vnd.curl.pcurl": "pcurl",
"application/vnd.dart": "dart",
"application/vnd.data-vision.rdz": "rdz",
"application/vnd.dece.data": "uvf",
"application/vnd.dece.ttml+xml": "uvt",
"application/vnd.dece.unspecified": "uvx",
"application/vnd.dece.zip": "uvz",
"application/vnd.denovo.fcselayout-link": "fe_launch",
"application/vnd.dna": "dna",
"application/vnd.dolby.mlp": "mlp",
"application/vnd.dpgraph": "dpg",
"application/vnd.dreamfactory": "dfac",
"application/vnd.ds-keypoint": "kpxx",
"application/vnd.dvb.ait": "ait",
"application/vnd.dvb.service": "svc",
"application/vnd.dynageo": "geo",
"application/vnd.ecowin.chart": "mag",
"application/vnd.enliven": "nml",
"application/vnd.epson.esf": "esf",
"application/vnd.epson.msf": "msf",
"application/vnd.epson.quickanime": "qam",
"application/vnd.epson.salt": "slt",
"application/vnd.epson.ssf": "ssf",
"application/vnd.eszigno3+xml": "es3",
"application/vnd.ezpix-album": "ez2",
"application/vnd.ezpix-package": "ez3",
"application/vnd.fdf": "fdf",
"application/vnd.fdsn.mseed": "mseed",
"application/vnd.fdsn.seed": "seed",
"application/vnd.flographit": "gph",
"application/vnd.fluxtime.clip": "ftc",
"application/vnd.framemaker": "fm",
"application/vnd.frogans.fnc": "fnc",
"application/vnd.frogans.ltf": "ltf",
"application/vnd.fsc.weblaunch": "fsc",
"application/vnd.fujitsu.oasys": "oas",
"application/vnd.fujitsu.oasys2": "oa2",
"application/vnd.fujitsu.oasys3": "oa3",
"application/vnd.fujitsu.oasysgp": "fg5",
"application/vnd.fujitsu.oasysprs": "bh2",
"application/vnd.fujixerox.ddd": "ddd",
"application/vnd.fujixerox.docuworks": "xdw",
"application/vnd.fujixerox.docuworks.binder": "xbd",
"application/vnd.fuzzysheet": "fzs",
"application/vnd.genomatix.tuxedo": "txd",
"application/vnd.geogebra.file": "ggb",
"application/vnd.geogebra.tool": "ggt",
"application/vnd.geometry-explorer": "gex gre",
"application/vnd.geonext": "gxt",
"application/vnd.geoplan": "g2w",
"application/vnd.geospace": "g3w",
"application/vnd.gmx": "gmx",
"application/vnd.google-earth.kml+xml": "kml",
"application/vnd.google-earth.kmz": "kmz",
"application/vnd.grafeq": "gqf gqs",
"application/vnd.groove-account": "gac",
"application/vnd.groove-help": "ghf",
"application/vnd.groove-identity-message": "gim",
"application/vnd.groove-injector": "grv",
"application/vnd.groove-tool-message": "gtm",
"application/vnd.groove-tool-template": "tpl",
"application/vnd.groove-vcard": "vcg",
"application/vnd.hal+xml": "hal",
"application/vnd.handheld-entertainment+xml": "zmm",
"application/vnd.hbci": "hbci",
"application/vnd.hhe.lesson-player": "les",
"application/vnd.hp-hpgl": "hpgl",
"application/vnd.hp-hpid": "hpid",
"application/vnd.hp-hps": "hps",
"application/vnd.hp-jlyt": "jlt",
"application/vnd.hp-pcl": "pcl",
"application/vnd.hp-pclxl": "pclxl",
"application/vnd.hydrostatix.sof-data": "sfd-hdstx",
"application/vnd.ibm.minipay": "mpy",
"application/vnd.ibm.modcap": "afp",
"application/vnd.ibm.rights-management": "irm",
"application/vnd.ibm.secure-container": "sc",
"application/vnd.iccprofile": "icc icm",
"application/vnd.igloader": "igl",
"application/vnd.immervision-ivp": "ivp",
"application/vnd.immervision-ivu": "ivu",
"application/vnd.insors.igm": "igm",
"application/vnd.intercon.formnet": "xpw",
"application/vnd.intergeo": "i2g",
"application/vnd.intu.qbo": "qbo",
"application/vnd.intu.qfx": "qfx",
"application/vnd.ipunplugged.rcprofile": "rcprofile",
"application/vnd.irepository.package+xml": "irp",
"application/vnd.is-xpr": "xpr",
"application/vnd.isac.fcs": "fcs",
"application/vnd.jam": "jam",
"application/vnd.jcp.javame.midlet-rms": "rms",
"application/vnd.jisp": "jisp",
"application/vnd.joost.joda-archive": "joda",
"application/vnd.kahootz": "ktz",
"application/vnd.kde.karbon": "karbon",
"application/vnd.kde.kchart": "chrt",
"application/vnd.kde.kformula": "kfo",
"application/vnd.kde.kivio": "flw",
"application/vnd.kde.kontour": "kon",
"application/vnd.kde.kpresenter": "kpr",
"application/vnd.kde.kspread": "ksp",
"application/vnd.kde.kword": "kwd",
"application/vnd.kenameaapp": "htke",
"application/vnd.kidspiration": "kia",
"application/vnd.kinar": "kne knp",
"application/vnd.koan": "skp",
"application/vnd.kodak-descriptor": "sse",
"application/vnd.las.las+xml": "lasxml",
"application/vnd.llamagraphics.life-balance.desktop": "lbd",
"application/vnd.llamagraphics.life-balance.exchange+xml": "lbe",
"application/vnd.lotus-1-2-3": "123",
"application/vnd.lotus-approach": "apr",
"application/vnd.lotus-freelance": "pre",
"application/vnd.lotus-notes": "nsf",
"application/vnd.lotus-organizer": "org",
"application/vnd.lotus-screencam": "scm",
"application/vnd.lotus-wordpro": "lwp",
"application/vnd.macports.portpkg": "portpkg",
"application/vnd.mcd": "mcd",
"application/vnd.medcalcdata": "mc1",
"application/vnd.mediastation.cdkey": "cdkey",
"application/vnd.mfer": "mwf",
"application/vnd.mfmp": "mfm",
"application/vnd.micrografx.flo": "flo",
"application/vnd.micrografx.igx": "igx",
"application/vnd.mif": "mif",
"application/vnd.mobius.daf": "daf",
"application/vnd.mobius.dis": "dis",
"application/vnd.mobius.mbk": "mbk",
"application/vnd.mobius.mqy": "mqy",
"application/vnd.mobius.msl": "msl",
"application/vnd.mobius.plc": "plc",
"application/vnd.mobius.txf": "txf",
"application/vnd.mophun.application": "mpn",
"application/vnd.mophun.certificate": "mpc",
"application/vnd.mozilla.xul+xml": "xul",
"application/vnd.ms-artgalry": "cil",
"application/vnd.ms-cab-compressed": "cab",
"application/vnd.ms-excel": "xls",
"application/vnd.ms-excel.addin.macroenabled.12": "xlam",
"application/vnd.ms-excel.sheet.binary.macroenabled.12": "xlsb",
"application/vnd.ms-excel.sheet.macroenabled.12": "xlsm",
"application/vnd.ms-excel.template.macroenabled.12": "xltm",
"application/vnd.ms-fontobject": "eot",
"application/vnd.ms-htmlhelp": "chm",
"application/vnd.ms-ims": "ims",
"application/vnd.ms-lrm": "lrm",
"application/vnd.ms-officetheme": "thmx",
"application/vnd.ms-pki.seccat": "cat",
"application/vnd.ms-pki.stl": "stl",
"application/vnd.ms-powerpoint": "ppt pps pot",
"application/vnd.ms-powerpoint.addin.macroenabled.12": "ppam",
"application/vnd.ms-powerpoint.presentation.macroenabled.12": "pptm",
"application/vnd.ms-powerpoint.slide.macroenabled.12": "sldm",
"application/vnd.ms-powerpoint.slideshow.macroenabled.12": "ppsm",
"application/vnd.ms-powerpoint.template.macroenabled.12": "potm",
"application/vnd.ms-project": "mpp mpt",
"application/vnd.ms-word.document.macroenabled.12": "docm",
"application/vnd.ms-word.template.macroenabled.12": "dotm",
"application/vnd.ms-works": "wps",
"application/vnd.ms-wpl": "wpl",
"application/vnd.ms-xpsdocument": "xps",
"application/vnd.mseq": "mseq",
"application/vnd.musician": "mus",
"application/vnd.muvee.style": "msty",
"application/vnd.mynfc": "taglet",
"application/vnd.neurolanguage.nlu": "nlu",
"application/vnd.nitf": "ntf nitf",
"application/vnd.noblenet-directory": "nnd",
"application/vnd.noblenet-sealer": "nns",
"application/vnd.noblenet-web": "nnw",
"application/vnd.nokia.n-gage.data": "ngdat",
"application/vnd.nokia.n-gage.symbian.install": "n-gage",
"application/vnd.nokia.radio-preset": "rpst",
"application/vnd.nokia.radio-presets": "rpss",
"application/vnd.novadigm.edm": "edm",
"application/vnd.novadigm.edx": "edx",
"application/vnd.novadigm.ext": "ext",
"application/vnd.oasis.opendocument.chart": "odc",
"application/vnd.oasis.opendocument.chart-template": "otc",
"application/vnd.oasis.opendocument.database": "odb",
"application/vnd.oasis.opendocument.formula": "odf",
"application/vnd.oasis.opendocument.formula-template": "odft",
"application/vnd.oasis.opendocument.graphics": "odg",
"application/vnd.oasis.opendocument.graphics-template": "otg",
"application/vnd.oasis.opendocument.image": "odi",
"application/vnd.oasis.opendocument.image-template": "oti",
"application/vnd.oasis.opendocument.presentation": "odp",
"application/vnd.oasis.opendocument.presentation-template": "otp",
"application/vnd.oasis.opendocument.spreadsheet": "ods",
"application/vnd.oasis.opendocument.spreadsheet-template": "ots",
"application/vnd.oasis.opendocument.text": "odt",
"application/vnd.oasis.opendocument.text-master": "odm",
"application/vnd.oasis.opendocument.text-template": "ott",
"application/vnd.oasis.opendocument.text-web": "oth",
"application/vnd.olpc-sugar": "xo",
"application/vnd.oma.dd2+xml": "dd2",
"application/vnd.openofficeorg.extension": "oxt",
"application/vnd.openxmlformats-officedocument.presentationml.presentation": "pptx",
"application/vnd.openxmlformats-officedocument.presentationml.slide": "sldx",
"application/vnd.openxmlformats-officedocument.presentationml.slideshow": "ppsx",
"application/vnd.openxmlformats-officedocument.presentationml.template": "potx",
"application/vnd.openxmlformats-officedocument.spreadsheetml.sheet": "xlsx",
"application/vnd.openxmlformats-officedocument.spreadsheetml.template": "xltx",
"application/vnd.openxmlformats-officedocument.wordprocessingml.document": "docx",
"application/vnd.openxmlformats-officedocument.wordprocessingml.template": "dotx",
"application/vnd.osgeo.mapguide.package": "mgp",
"application/vnd.osgi.dp": "dp",
"application/vnd.osgi.subsystem": "esa",
"application/vnd.palm": "pdb pqa oprc",
"application/vnd.pawaafile": "paw",
"application/vnd.pg.format": "str",
"application/vnd.pg.osasli": "ei6",
"application/vnd.picsel": "efif",
"application/vnd.pmi.widget": "wg",
"application/vnd.pocketlearn": "plf",
"application/vnd.powerbuilder6": "pbd",
"application/vnd.previewsystems.box": "box",
"application/vnd.proteus.magazine": "mgz",
"application/vnd.publishare-delta-tree": "qps",
"application/vnd.pvi.ptid1": "ptid",
"application/vnd.quark.quarkxpress": "qxd",
"application/vnd.realvnc.bed": "bed",
"application/vnd.recordare.musicxml": "mxl",
"application/vnd.recordare.musicxml+xml": "musicxml",
"application/vnd.rig.cryptonote": "cryptonote",
"application/vnd.rim.cod": "cod",
"application/vnd.rn-realmedia": "rm",
"application/vnd.rn-realmedia-vbr": "rmvb",
"application/vnd.route66.link66+xml": "link66",
"application/vnd.sailingtracker.track": "st",
"application/vnd.seemail": "see",
"application/vnd.sema": "sema",
"application/vnd.semd": "semd",
"application/vnd.semf": "semf",
"application/vnd.shana.informed.formdata": "ifm",
"application/vnd.shana.informed.formtemplate": "itp",
"application/vnd.shana.informed.interchange": "iif",
"application/vnd.shana.informed.package": "ipk",
"application/vnd.simtech-mindmapper": "twd",
"application/vnd.smaf": "mmf",
"application/vnd.smart.teacher": "teacher",
"application/vnd.solent.sdkm+xml": "sdkm",
"application/vnd.spotfire.dxp": "dxp",
"application/vnd.spotfire.sfs": "sfs",
"application/vnd.stardivision.calc": "sdc",
"application/vnd.stardivision.draw": "sda",
"application/vnd.stardivision.impress": "sdd",
"application/vnd.stardivision.math": "smf",
"application/vnd.stardivision.writer": "sdw",
"application/vnd.stardivision.writer-global": "sgl",
"application/vnd.stepmania.package": "smzip",
"application/vnd.stepmania.stepchart": "sm",
"application/vnd.sun.xml.calc": "sxc",
"application/vnd.sun.xml.calc.template": "stc",
"application/vnd.sun.xml.draw": "sxd",
"application/vnd.sun.xml.draw.template": "std",
"application/vnd.sun.xml.impress": "sxi",
"application/vnd.sun.xml.impress.template": "sti",
"application/vnd.sun.xml.math": "sxm",
"application/vnd.sun.xml.writer": "sxw",
"application/vnd.sun.xml.writer.global": "sxg",
"application/vnd.sun.xml.writer.template": "stw",
"application/vnd.sus-calendar": "sus",
"application/vnd.svd": "svd",
"application/vnd.symbian.install": "sis",
"application/vnd.syncml+xml": "xsm",
"application/vnd.syncml.dm+wbxml": "bdm",
"application/vnd.syncml.dm+xml": "xdm",
"application/vnd.tao.intent-module-archive": "tao",
"application/vnd.tcpdump.pcap": "pcap",
"application/vnd.tmobile-livetv": "tmo",
"application/vnd.trid.tpt": "tpt",
"application/vnd.triscape.mxs": "mxs",
"application/vnd.trueapp": "tra",
"application/vnd.ufdl": "ufdl",
"application/vnd.uiq.theme": "utz",
"application/vnd.umajin": "umj",
"application/vnd.unity": "unityweb",
"application/vnd.uoml+xml": "uoml",
"application/vnd.vcx": "vcx",
"application/vnd.visio": "vsd",
"application/vnd.visionary": "vis",
"application/vnd.vsf": "vsf",
"application/vnd.wap.wbxml": "wbxml",
"application/vnd.wap.wmlc": "wmlc",
"application/vnd.wap.wmlscriptc": "wmlsc",
"application/vnd.webturbo": "wtb",
"application/vnd.wolfram.player": "nbp",
"application/vnd.wordperfect": "wpd",
"application/vnd.wqd": "wqd",
"application/vnd.wt.stf": "stf",
"application/vnd.xara": "xar",
"application/vnd.xfdl": "xfdl",
"application/vnd.yamaha.hv-dic": "hvd",
"application/vnd.yamaha.hv-script": "hvs",
"application/vnd.yamaha.hv-voice": "hvp",
"application/vnd.yamaha.openscoreformat": "osf",
"application/vnd.yamaha.openscoreformat.osfpvg+xml": "osfpvg",
"application/vnd.yamaha.smaf-audio": "saf",
"application/vnd.yamaha.smaf-phrase": "spf",
"application/vnd.yellowriver-custom-menu": "cmp",
"application/vnd.zul": "zir",
"application/vnd.zzazz.deck+xml": "zaz",
"application/voicexml+xml": "vxml",
"application/widget": "wgt",
"application/winhlp": "hlp",
"application/wsdl+xml": "wsdl",
"application/wspolicy+xml": "wspolicy",
"application/x-7z-compressed": "7z",
"application/x-abiword": "abw",
"application/x-ace-compressed": "ace",
"application/x-apple-diskimage": "dmg",
"application/x-authorware-bin": "aab",
"application/x-authorware-map": "aam",
"application/x-authorware-seg": "aas",
"application/x-bcpio": "bcpio",
"application/x-bittorrent": "torrent",
"application/x-blorb": "blb",
"application/x-bzip": "bz",
"application/x-bzip2": "bz2",
"application/x-cbr": "cbr",
"application/x-cdlink": "vcd",
"application/x-cfs-compressed": "cfs",
"application/x-chat": "chat",
"application/x-chess-pgn": "pgn",
"application/x-conference": "nsc",
"application/x-cpio": "cpio",
"application/x-csh": "csh",
"application/x-debian-package": "deb",
"application/x-dgc-compressed": "dgc",
"application/x-director": "dir",
"application/x-doom": "wad",
"application/x-dtbncx+xml": "ncx",
"application/x-dtbook+xml": "dtb",
"application/x-dtbresource+xml": "res",
"application/x-dvi": "dvi",
"application/x-envoy": "evy",
"application/x-eva": "eva",
"application/x-font-bdf": "bdf",
"application/x-font-ghostscript": "gsf",
"application/x-font-linux-psf": "psf",
"application/x-font-otf": "otf",
"application/x-font-pcf": "pcf",
"application/x-font-snf": "snf",
"application/x-font-ttf": "ttf",
"application/x-font-type1": "pfa",
"application/x-font-woff": "woff",
"application/x-freearc": "arc",
"application/x-futuresplash": "spl",
"application/x-gca-compressed": "gca",
"application/x-glulx": "ulx",
"application/x-gnumeric": "gnumeric",
"application/x-gramps-xml": "gramps",
"application/x-gtar": "gtar",
"application/x-hdf": "hdf",
"application/x-install-instructions": "install",
"application/x-iso9660-image": "iso",
"application/x-java-jnlp-file": "jnlp",
"application/x-latex": "latex",
"application/x-lzh-compressed": "lzh",
"application/x-mie": "mie",
"application/x-mobipocket-ebook": "prc",
"application/x-ms-application": "application",
"application/x-ms-shortcut": "lnk",
"application/x-ms-wmd": "wmd",
"application/x-ms-wmz": "wmz",
"application/x-ms-xbap": "xbap",
"application/x-msaccess": "mdb",
"application/x-msbinder": "obd",
"application/x-mscardfile": "crd",
"application/x-msclip": "clp",
"application/x-msdownload": "exe",
"application/x-msmediaview": "mvb",
"application/x-msmetafile": "wmf",
"application/x-msmoney": "mny",
"application/x-mspublisher": "pub",
"application/x-msschedule": "scd",
"application/x-msterminal": "trm",
"application/x-mswrite": "wri",
"application/x-netcdf": "nc",
"application/x-nzb": "nzb",
"application/x-pkcs12": "p12",
"application/x-pkcs7-certificates": "p7b",
"application/x-pkcs7-certreqresp": "p7r",
"application/x-rar-compressed": "rar",
"application/x-research-info-systems": "ris",
"application/x-sh": "sh",
"application/x-shar": "shar",
"application/x-shockwave-flash": "swf",
"application/x-silverlight-app": "xap",
"application/x-sql": "sql",
"application/x-stuffit": "sit",
"application/x-stuffitx": "sitx",
"application/x-subrip": "srt",
"application/x-sv4cpio": "sv4cpio",
"application/x-sv4crc": "sv4crc",
"application/x-t3vm-image": "t3",
"application/x-tads": "gam",
"application/x-tar": "tar",
"application/x-tcl": "tcl",
"application/x-tex": "tex",
"application/x-tex-tfm": "tfm",
"application/x-texinfo": "texinfo",
"application/x-tgif": "obj",
"application/x-ustar": "ustar",
"application/x-wais-source": "src",
"application/x-x509-ca-cert": "der",
"application/x-xfig": "fig",
"application/x-xliff+xml": "xlf",
"application/x-xpinstall": "xpi",
"application/x-xz": "xz",
"application/x-zmachine": "z1",
"application/xaml+xml": "xaml",
"application/xcap-diff+xml": "xdf",
"application/xenc+xml": "xenc",
"application/xhtml+xml": "xhtml",
"application/xml": "xml",
"application/xml-dtd": "dtd",
"application/xop+xml": "xop",
"application/xproc+xml": "xpl",
"application/xslt+xml": "xslt",
"application/xspf+xml": "xspf",
"application/xv+xml": "mxml",
"application/yang": "yang",
"application/yin+xml": "yin",
"application/zip": "zip",
"audio/adpcm": "adp",
"audio/basic": "au",
"audio/midi": "mid",
"audio/mp4": "mp4a",
"audio/mpeg": "mpga",
"audio/ogg": "oga",
"audio/s3m": "s3m",
"audio/silk": "sil",
"audio/vnd.dece.audio": "uva",
"audio/vnd.digital-winds": "eol",
"audio/vnd.dra": "dra",
"audio/vnd.dts": "dts",
"audio/vnd.dts.hd": "dtshd",
"audio/vnd.lucent.voice": "lvp",
"audio/vnd.ms-playready.media.pya": "pya",
"audio/vnd.nuera.ecelp4800": "ecelp4800",
"audio/vnd.nuera.ecelp7470": "ecelp7470",
"audio/vnd.nuera.ecelp9600": "ecelp9600",
"audio/vnd.rip": "rip",
"audio/webm": "weba",
"audio/x-aac": "aac",
"audio/x-aiff": "aif",
"audio/x-caf": "caf",
"audio/x-flac": "flac",
"audio/x-matroska": "mka",
"audio/x-mpegurl": "m3u",
"audio/x-ms-wax": "wax",
"audio/x-ms-wma": "wma",
"audio/x-pn-realaudio": "ram",
"audio/x-pn-realaudio-plugin": "rmp",
"audio/x-wav": "wav",
"audio/xm": "xm",
"chemical/x-cdx": "cdx",
"chemical/x-cif": "cif",
"chemical/x-cmdf": "cmdf",
"chemical/x-cml": "cml",
"chemical/x-csml": "csml",
"chemical/x-xyz": "xyz",
"image/bmp": "bmp",
"image/cgm": "cgm",
"image/g3fax": "g3",
"image/gif": "gif",
"image/ief": "ief",
"image/jpeg": "jpeg",
"image/ktx": "ktx",
"image/png": "png",
"image/prs.btif": "btif",
"image/sgi": "sgi",
"image/svg+xml": "svg svgz",
"image/tiff": "tiff tif",
"image/vnd.adobe.photoshop": "psd",
"image/vnd.dece.graphic": "uvi",
"image/vnd.dvb.subtitle": "sub",
"image/vnd.djvu": "djvu",
"image/vnd.dwg": "dwg",
"image/vnd.dxf": "dxf",
"image/vnd.fastbidsheet": "fbs",
"image/vnd.fpx": "fpx",
"image/vnd.fst": "fst",
"image/vnd.fujixerox.edmics-mmr": "mmr",
"image/vnd.fujixerox.edmics-rlc": "rlc",
"image/vnd.ms-modi": "mdi",
"image/vnd.ms-photo": "wdp",
"image/vnd.net-fpx": "npx",
"image/vnd.wap.wbmp": "wbmp",
"image/vnd.xiff": "xif",
"image/webp": "webp",
"image/x-3ds": "3ds",
"image/x-cmu-raster": "ras",
"image/x-cmx": "cmx",
"image/x-freehand": "fh",
"image/x-icon": "ico",
"image/x-mrsid-image": "sid",
"image/x-pcx": "pcx",
"image/x-pict": "pic",
"image/x-portable-anymap": "pnm",
"image/x-portable-bitmap": "pbm",
"image/x-portable-graymap": "pgm",
"image/x-portable-pixmap": "ppm",
"image/x-rgb": "rgb",
"image/x-tga": "tga",
"image/x-xbitmap": "xbm",
"image/x-xpixmap": "xpm",
"image/x-xwindowdump": "xwd",
"message/rfc822": "eml mime",
"model/iges": "igs",
"model/mesh": "mesh",
"model/vnd.collada+xml": "dae",
"model/vnd.dwf": "dwf",
"model/vnd.gdl": "gdl",
"model/vnd.gtw": "gtw",
"model/vnd.mts": "mts",
"model/vnd.vtu": "vtu",
"model/vrml": "wrl vrml",
"model/x3d+binary": "x3db",
"model/x3d+vrml": "x3dv",
"model/x3d+xml": "x3d",
"text/cache-manifest": "appcache",
"text/calendar": "ics ifb",
"text/css": "css",
"text/csv": "csv",
"text/html": "html",
"text/n3": "n3",
"text/plain": "txt",
"text/prs.lines.tag": "dsc",
"text/richtext": "rtx",
"text/sgml": "sgml sgm",
"text/tab-separated-values": "tsv",
"text/troff": "t",
"text/turtle": "ttl",
"text/uri-list": "uri",
"text/vcard": "vcard",
"text/vnd.curl": "curl",
"text/vnd.curl.dcurl": "dcurl",
"text/vnd.curl.scurl": "scurl",
"text/vnd.curl.mcurl": "mcurl",
"text/vnd.dvb.subtitle": "sub",
"text/vnd.fly": "fly",
"text/vnd.fmi.flexstor": "flx",
"text/vnd.graphviz": "gv",
"text/vnd.in3d.3dml": "3dml",
"text/vnd.in3d.spot": "spot",
"text/vnd.sun.j2me.app-descriptor": "jad",
"text/vnd.wap.wml": "wml",
"text/vnd.wap.wmlscript": "wmls",
"text/x-asm": "s asm",
"text/x-c": "c",
"text/x-fortran": "f",
"text/x-java-source": "java",
"text/x-opml": "opml",
"text/x-pascal": "p pas",
"text/x-nfo": "nfo",
"text/x-shellscript": "sh",
"text/x-setext": "etx",
"text/x-sfv": "sfv",
"text/x-tex": "tex",
"text/x-uuencode": "uu",
"text/x-vcalendar": "vcs",
"text/x-vcard": "vcf",
"video/3gpp": "3gp",
"video/3gpp2": "3g2",
"video/h261": "h261",
"video/h263": "h263",
"video/h264": "h264",
"video/jpeg": "jpgv",
"video/jpm": "jpm",
"video/mj2": "mj2",
"video/mp4": "mp4",
"video/mpeg": "mpeg",
"video/ogg": "ogv",
"video/quicktime": "qt",
"video/vnd.dece.hd": "uvh",
"video/vnd.dece.mobile": "uvm",
"video/vnd.dece.pd": "uvp",
"video/vnd.dece.sd": "uvs",
"video/vnd.dece.video": "uvv",
"video/vnd.dvb.file": "dvb",
"video/vnd.fvt": "fvt",
"video/vnd.mpegurl": "m4u",
"video/vnd.ms-playready.media.pyv": "pyv",
"video/vnd.uvvu.mp4": "uvvu",
"video/vnd.vivo": "viv",
"video/webm": "webm",
"video/x-f4v": "f4v",
"video/x-fli": "fli",
"video/x-flv": "flv",
"video/x-m4v": "m4v",
"video/x-matroska": "mkv",
"video/x-mng": "mng",
"video/x-ms-asf": "asf",
"video/x-ms-vob": "vob",
"video/x-ms-wm": "wm",
"video/x-ms-wmv": "wmv",
"video/x-ms-wmx": "wmx",
"video/x-ms-wvx": "wvx",
"video/x-msvideo": "avi",
"video/x-sgi-movie": "movie",
"video/x-smv": "smv",
"x-conference/x-cooltalk": "ice",
}
const letterBytes = "abcdefghijklmnopqrstuvwxyz1234567890"
const (
letterIdxBits = 6 // 6 bits to represent a letter index