go.chromium.org/luci@v0.0.0-20240309015107-7cdc2e660f33/luciexe/host/buildmerge/util.go (about)

     1  // Copyright 2021 The LUCI Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package buildmerge
    16  
    17  import (
    18  	"strings"
    19  
    20  	"go.chromium.org/luci/common/errors"
    21  	"go.chromium.org/luci/logdog/common/types"
    22  )
    23  
    24  // absolutizeURLs absolutizes the provided `logURL` and `viewURL`.
    25  //
    26  // No-op if both `logURL` and `viewURL` are absolute urls. Absolute url here
    27  // means url that has valid scheme. A valid scheme must be
    28  // `[a-zA-Z][a-zA-Z0-9+-.]*“ according to
    29  // https://datatracker.ietf.org/doc/html/rfc3986#section-3.1
    30  //
    31  // If `logURL` is relative, calculate the return urls using `calcFn`. The
    32  // provided `viewURL` will be omitted.
    33  //
    34  // Returns error if any of the following conditions are true:
    35  //   - `logURL` is an absolute url but `viewURL` is empty.
    36  //   - `logURL` is an absolute url but `viewURL` is not an absolute url.
    37  //   - `logURL` is a relative url but not a valid logdog stream.
    38  //
    39  // The input `logURL` and `viewURL` will be returned verbatim on errors.
    40  func absolutizeURLs(logURL, viewURL string, ns types.StreamName, calcFn CalcURLFn) (retLogURL, retViewURL string, err error) {
    41  	retLogURL, retViewURL = logURL, viewURL
    42  	if isAbs(logURL) {
    43  		switch {
    44  		case viewURL == "":
    45  			return retLogURL, retViewURL, errors.Reason("absolute log url is provided %q but view url is empty", logURL).Err()
    46  		case !isAbs(viewURL):
    47  			return retLogURL, retViewURL, errors.Reason("expected absolute view url, got %q", viewURL).Err()
    48  		}
    49  		// both urls are absolute.
    50  		return retLogURL, retViewURL, nil
    51  	}
    52  
    53  	stream := types.StreamName(logURL)
    54  	if serr := stream.Validate(); serr != nil {
    55  		return retLogURL, retViewURL, errors.Annotate(serr, "bad log url %q", logURL).Err()
    56  	}
    57  	retLogURL, retViewURL = calcFn(ns, stream)
    58  	return retLogURL, retViewURL, nil
    59  }
    60  
    61  func isAbs(url string) bool {
    62  	idx := strings.Index(url, "://")
    63  	if idx <= 0 {
    64  		return false
    65  	}
    66  	scheme := url[:idx]
    67  	for i := 0; i < len(scheme); i++ {
    68  		c := scheme[i]
    69  		switch {
    70  		case 'a' <= c && c <= 'z' || 'A' <= c && c <= 'Z':
    71  		// always valid
    72  		case '0' <= c && c <= '9' || c == '+' || c == '-' || c == '.':
    73  			if i != 0 {
    74  				return false
    75  			}
    76  		}
    77  	}
    78  	return true
    79  }