Review Board and Subversion Hooks

Review Board is quite nice... it has a handy program for posting reviews (postreview)... and you can integrate this into your subversion hook scripts quite nicely...

But what if you want to automate submitting reviews on only parts of your code base...

What I want is to be able to set a property on a folder and then any time a file is changed in that folder or it's children, then a review will automatically be scheduled...

So I wrote the following C/C++ helper (because we would potentially be forking a lot of svnlook processes) which checks to see if a property is set on any of the changed paths or the changed path parents.

/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements.  See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership.  The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License.  You may obtain a copy of the License at
*
*   http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied.  See the License for the
* specific language governing permissions and limitations
* under the License.
*/

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/wait.h>

/**
 * Returns a stream for the output of dirs-changed from svnlook.
 */
FILE *svnlook_dirs_changed(char *svnlook, char *repo, char *rev) {
    char *cmd;

    cmd = (char *) malloc(strlen(svnlook) + strlen(" dirs-changed ") + strlen(repo) + strlen(" -r ") + strlen(rev) + 1);
    strcpy(cmd, svnlook);
    strcat(cmd, " dirs-changed ");
    strcat(cmd, repo);
    strcat(cmd, " -r ");
    strcat(cmd, rev);
    return (FILE *) popen(cmd, "r");
}

/**
 * Uses svnlook to check and see if the specified property is set on the specified path in the specified repository.
 */
int svnlook_is_prop_set(char *svnlook, char *repopath, char *propname, char *path) {
    int status;
    pid_t pid;
    pid = fork();
    if (pid == 0) {
        fclose(stdin);
        FILE* fp = fopen("/dev/null", "w+");
        if (fileno(fp) != STDIN_FILENO) {
            _exit(EXIT_FAILURE);
        }
        if (dup2(STDIN_FILENO, STDOUT_FILENO) == -1) {
            _exit(EXIT_FAILURE);
        }
        if (dup2(STDIN_FILENO, STDERR_FILENO) == -1) {
            _exit(EXIT_FAILURE);
        }
        execl(svnlook, svnlook, "pg", repopath, propname, path, NULL);
        printf("exit failure\n");
        _exit(EXIT_FAILURE);
    } else if (pid < 0) {
        status = -1;
    } else {
        if (waitpid(pid, &status, 0) != pid) {
            status = -1;
        }
    }
    return status;
}

/**
 * Checks to see if any of the directories from the stream have the specified property set.
 */
int check_svn_dirs(FILE* fdirschanged, char *svnlook,char *repopath, char *revnum, char *propname, int showallpaths) {
    char line[1024];
    int rv = 0;;
    while (fgets(line, sizeof line, fdirschanged)) {
        for (unsigned int i = 0; i < sizeof line; i++) {
            if (line[i] == '\n') {
                line[i] = 0;
                for (int j = i; j > 0; j--) {
                    if (line[j] == '/') {
                        line[j] = 0;
                        if (0 == svnlook_is_prop_set(svnlook, repopath, propname, line)) {
                            printf("%s/\n", line);
                            if (!showallpaths) {
                                return 1;
                            } else {
                                rv = 1;
                            }
                        }
                    }
                }
                line[0] = 0;
                if (0 == svnlook_is_prop_set(svnlook, repopath, propname, line)) {
                    printf("/\n");
                    if (!showallpaths) {
                        return 1;
                    } else {
                        rv = 1;
                    }
                }
                break;
            } // else it's a really long path and I'm refusing to check it!
            
        }
    }
    return rv;
}

int main(int argc, char **argv) {
    FILE *fpipe;

    char *svnlook = "/usr/bin/svnlook";
    char *repopath = "..";
    char *revnum = NULL;
    char *propname = NULL;
    int showallpaths = 0;

    int index = 1;
    int help = 0;
    while (index < argc) {
        if (strcmp("--svn-look", argv[index]) == 0) {
            index++;
            if (index < argc) {
                svnlook = argv[index];
            } else {
                help = 1;
                break;
            }
        } else if (strcmp("-r", argv[index]) == 0) {
            index++;
            if (index < argc) {
                revnum = argv[index];
            } else {
                help = 1;
                break;
            }
        } else if (strcmp("--repo", argv[index]) == 0) {
            index++;
            if (index < argc) {
                repopath = argv[index];
            } else {
                help = 1;
                break;
            }
        } else if (strcmp("--property", argv[index]) == 0) {
            index++;
            if (index < argc) {
                propname = argv[index];
            } else {
                help = 1;
                break;
            }
        } else if (strcmp("--show-all-paths", argv[index]) == 0) {
            showallpaths = 1;
        } else if (strcmp("--help", argv[index]) == 0 || strcmp("-h", argv[index]) == 0 || strcmp("-?", argv[index]) == 0) {
            help = 1;
            break;
        } else {
            help = 1;
            break;
        }

        index++;
    }

    if (help || svnlook == NULL || repopath == NULL || revnum == NULL || propname == NULL) {
        printf("Syntax: %s options\n", argv[0]);
        printf("Options:\n");
        printf("    --svn-look PATH     Specify an alternative svnlook binary location (default /usr/bin/svnlook)\n");
        printf("    --repo PATH         Specify the repository to work against (required)\n");
        printf("    -r REVNUM           Specify the revision to process (required)\n");
        printf("    -property NAME      Specify the property to check (required)\n");
        printf("    --show-all-paths    Shows all the changed paths with the property rather than just the first (optional)\n");
        return 2;
    }

    int rv = 0;
    fpipe = svnlook_dirs_changed(svnlook, repopath, revnum);
    if (fpipe) {
        rv = check_svn_dirs(fpipe, svnlook, repopath, revnum, propname, showallpaths);
        pclose(fpipe);
    }
    return rv;
}

Now I should warn you that it's a wee while since I wrote C/C++, so apologies if the above is not perfect... it works for me.

Next I use a post-commit.sh script to check for my property:

#!/bin/bash
#
# Licensed to the Apache Software Foundation (ASF) under one
# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
#

path=$(/usr/bin/svnlook props --repo "$1" -r $2 --property reviewboard:autoreview)
if [ $? == 1 ]; then
  if [ $(svnlook changed "$1" -r $2 | sed -e "/^_.*/d;" | wc -l) -eq 0 ] ; then 
    # Commit does not contain changed files, only changed properties
    exit 0
  fi
  people=$(for p in $(/usr/bin/svnlook props --repo "$1" -r $2 --property reviewboard:autoreview --show-all-paths); \
           do /usr/bin/svnlook pg "$1" reviewboard:autoreview "$p"; echo ""; done \
           | sed -e 's/[, \t]/\n/g;' | sort -u | tr '\n' ',' | sed -e "s/,$//;")
  post-review --server=... --username=... --password=... --submit-as=$(/usr/bin/svnlook author "$1" "$2") \
        --repository-url=... --revision-range=$(($2-1)):$2 "--description=$(/usr/bin/svnlook log "$1" -r "$2")" \
        "--summary=Commit r$2" "--target-people=$people" --publish
fi
exit 0

And now, as if by magic, all I need to do is set the property reviewboard:autoreview to the list of reviewboard usernames to be reviewers and then any time there is a commit on the folder with the property set, a review is automagically scheduled.

Lovely...

Now all I need to do is tone down how often reviewboard sends emails!