1	Modulo II Software Configuration Management - SCM Professor Ismael H F Santos – ismael@tecgraf.puc-rio.br
2	Bibliografia Introduction to Apache Maven 2 Tutorial ibm developerWorks: Introduction to Maven 2 http://www.javaworld.com/javaworld/jw-12-2005/jw-12-2005-maven.html
3	Ementa SCM – Introducao Subversion Maven SCM plugin
4	MTSW-Java
5	Version Control System operations Initialize Add Files Commit View History Share Update Revert Branch
6	Remote Users
7	Subversion Architecture SVN Clients & Server SVN Repository
8	The Problem of File-Sharing Problem to avoid !!!
9	The Lock-Modify-Unlock Solution Used by Many version control systems The repository allows only one person to change a file at a time. This exclusivity policy is managed using locks. Very restritive solution, lock related problems
10	The Copy-Modify-Merge Solution Subversion, CVS, and other version control systems use it Users can work in parallel, never waiting for one another. When people work on the same files, it turns out that most of their concurrent changes don't overlap at all;
11	The Copy-Modify-Merge Solution conflicts are infrequent. the amount of time it takes to resolve conflicts is far less than the time lost by a locking system.
12	MTSW-Java
13	Subversion Basics Open Source http://subversion.tigris.org/ Designed for remote users Unreserved checkouts Similar to CVS Checkout, edit, merge, commit
14	Subversion Basics Many clients possible Command-line client (included) Windows GUI client (in process) Other clients (more GUIs, integration with IDEs, etc) Apache-based network server WebDAV-based network protocol High performance, scalable, secure, and more
15	Why Open Source? If it is great, then it could replace CVS Widespread usage would establish it as a legitimate tool More and better clients are possible Peer review and testing Community feedback and contributions
16	Basic Method of Operation Similar to CVS Unreserved instead of reserved Client-side working copies Four basic steps Check out a “working copy” Make any edits Merge changes from server Commit your changes
17	Clients Command-line client comes standard Windows client: TortoiseSVN Linux: GTK (X Windows) client Integration with IDEs: SubEclipse plugin WebDAV clients, too! Microsoft Windows, Office, and others Open source clients such as cadaver, Nautilus, and Goliat
18	Apache as a Server WebDAV (DeltaV) for the network protocol Apache 2.0 and mod_dav mod_dav_svn as glue to Subversion High performance, scalability, and robust SSL provides encryption and authentication Proxy/firewall friendly
19	Subversion vs CVS Most CVS features Directory versioning Metadata Atomic commits Branching and tagging are cheap Designed for the network Better binary file handling Layered library design
20	Revision Numbering Global revision number rather than per-file Allows you to talk about “revision 2524” Unique identifier for a state of your project Simple way to tag (next slide) Each revision corresponds to a single commit Contains author, log message, and date
21	Tagging and Branching Subversion implements “cheap copies” Branches are just copies of the main trunk Make changes in the copy Merge the changes back to the main trunk Tags are copies which are never changed Might not even be necessary if you simply record the global revision number that built your product
22	Example Repository Layout
23	Authentication CVS uses a custom authentication mechanism Part of CVS’s custom (non-standard) protocol “I LOVE YOU” or “I HATE YOU” pserver sends passwords in the clear Alternate authentication schemes kserver, gserver SSH tunneling Subversion uses HTTP as its protocol Integrates with existing authentication systems Standardized!
24	Modules CVS modules Live in CVSROOT The “modules” file Only the administrator can alter module definitions Only apply to checkout Changes are not detected during “cvs update” Subversion modules Directory property (“svn:externals”) Users can define them, edit them, inspect them Attach to any directory Versioned, as with any property Changes are detected during “svn update”
25	Keywords CVS keywords are automatically expanded User must explicitly disable this behavior Risk of destroying a binary file Subversion keywords are optionally expanded User must proactively enable keyword expansion The user states the set of keywords to expand (some or all) The behavior is controlled by a property: svn:keywords
26	Directory Versioning Directories are versioned items Deletes and moves are recorded Copy sources are remembered
27	Metadata Any file or directory can store properties Properties are name/value pairs Some standard properties exist svn:ignore svn:mime-type svn:eol-style etc. User-defined properties are allowed Property values can be text or binary
28	Improved Features (1 of 2) Atomic commits CVS can commit one file, fail on the second Subversion commits all changes, or nothing Binary file handling Subversion uses MIME types Binary diffs Newline and keyword handling is improved Subversion does not munge your files until you tell it to
29	Improved Features (2 of 2) Designed for the network CVS had network support “bolted on” Two code paths to maintain Authentication poorly integrated Subversion has network support (based on WebDAV/DeltaV) that was planned from the very early stages Binary diffs in both directions
30	Layered Library Design Many levels for interaction High-level client Repository access (local, remote, pipe, etc) Direct access to the storage Enables scripting Clients can share a lot of code The command-line client is a small application built on top of the high-level client library GUI clients can also use the high-level library Library-based enables third-parties
31	Details: repositories Subversion uses URLs for repository locations http://svn.collab.net/repos/svn/ is the actual URL for Subversion itself Web browsers can view the “head” Full ViewCVS-like functionality coming soon “file” URLs are also allowed for local access Example: file:///home/gstein/repos/testing/
32	Details: checkout Creates a local working copy
33	Details: commit Commit changes to the repository
34	Details: add Add new files and directories
35	Details: mkdir Simplify directory creation
36	Details: mkdir <URL> Quickly sets up a new repository directory
37	Details: delete Delete files and directories
38	Details: delete <URL> Delete items directly from the repository Great for removing obsolete tags or branches
39	Details: update Retrieve changes made by other users
40	Details: status Shows changes to the working copy
41	Details: copy Copy files and directories Source and destination can be working copies and/or direct repository references
42	Details: move Move files and directories The source and destination must both be working copy references, or they must both be URLs
43	Details: diff Shows changes to the working copy
44	Details: log Shows changes that have been committed
45	Details: revert Reverts changes made to a working copy Replaces CVS’s idiom of “rm file; cvs update file”
46	Details: info Provide information about files / directories
47	Details: properties Five different commands for manipulating properties on files and directories
48	Details: merge Merges changes from two sources/revisions into a target
49	Three-way Merge
50	Details: resolve Cleans up conflict files left from a conflict during “svn update” or “svn merge”
51	Details: import Loads new content into a repository
52	Details: export Just like a checkout, but the .svn administrative subdirectories are omitted
53	Details: switch Switch a working copy to a branch
54	Additional Tools cvs2svn ViewSVN Hook scripts Send commit emails Simple ACL support Simple reserved checkouts Repository backup Libraries, scripting, svnlook
55	MTSW-Java
56	Maven in Development
57	Maven Features/Functions Manage External Dependencies Retrieve Source from SCM Build Artifacts Run Tests Package Artifacts (jar,war,zip,tar…) Generate Project Reports Create Website of Project Info Deploy Website and Distributions Extensible via Plugins
58	Maven Overview
59	Coding Standards & Maven Maven Provides a Plug-In Architecture for 3^rd Party Applications Check Style Description Development Tool for Java Programmers Flexible Enough to Support Any Standard Checks Coding Style and Coding Structure Optional Checks Include J2EE Requirements
60	Coding Standards & Maven
61	SCM Plugin has 16 goals Seamlessly integrates Maven processes with your SCM repository. mvn scm:diff Creates UNIX diff file mvn scm:tag mvn scm:status Dozens of SCM systems supported. CVS, Subversion, Git
62	Maven SCM Support Seamlessly integrates Maven processes with your SCM repository. scm:branch - branch the project scm:validate - validate the scm information in the pom scm:add - command to add file scm:unedit - command to stop editing the working copy scm:export - command to get a fresh exported copy scm:bootstrap - command to checkout and build a project scm:changelog - command to show the source code revisions scm:list - command for get the list of project files
63	SCM Plugin The scm plugin maps a lot of commands to a variety of scm implementations checkin - commit the changes to the remote repository (scm server). update - updates the local working copy with the one from the remote repository (scm server).
64	SCM Plugin Configuration ... <scm> <connection> scm:svn:http://somerepository.com/svn_repo/trunk </connection> <developerConnection> scm:svn:https://somerepository.com/svn_repo/trunk </developerConnection> <url>http://somerepository.com/view.cvs</url> </scm> ... </project> http://maven.apache.org/scm/maven-scm-plugin/usage.html
65	SCM Plugin Configuration ... <scm> <connection> scm:svn:http://somerepository.com/svn_repo/trunk </connection> <developerConnection> scm:svn:https://somerepository.com/svn_repo/trunk </developerConnection> <url>http://somerepository.com/view.cvs</url> </scm> ... </project> http://maven.apache.org/scm/maven-scm-plugin/usage.html
66	SCM Plugin Bootstrapping a Project Using a POM http://maven.apache.org/scm/maven-scm-plugin/examples/bootstrapping-with-pom.html Other SCM Commands http://maven.apache.org/scm/maven-scm-plugin/examples/scm-advance-features.html