Add packfiles to plumbing section

5 files changed, 91 insertions, 7 deletions

diff --git a/src/code/packfiles/1 b/src/code/packfiles/1
new file mode 100644
index 0000000..24819a0
--- /dev/null
+++ b/src/code/packfiles/1
@@ -0,0 +1,16 @@
+± git rev-list --objects --all | head -1 | \
+  git pack-objects --stdout | xxd
+Counting objects: 1, done.
+Total 1 (delta 0), reused 0 (delta 0)
+00000000: 5041 434b 0000 0002 0000 0001 950e 789c  PACK..........x.
+00000010: 9d8c 510e c220 1005 ff39 c55e 40b3 0894  ..Q.. ...9.^@...
+00000020: 2531 c6ab 00bb 4d1b 6931 089e 5f8d 9ec0  %1....M.i1.._...
+00000030: bf37 93cc eb4d 0426 4ade 7967 2741 ca9a  .7...M.&J.yg'A..
+00000040: 031a 9389 f024 9645 6764 173e 3293 bac7  .....$.Egd.>2...
+00000050: 267b 8729 4844 09c6 2349 326f c83c 3b66  &{.)HD..#I2o.<;f
+00000060: 4a12 58cf 19a3 f17a 162d 2a8e bed4 06b7  J.X....z.-*.....
+00000070: 144b a903 cebf 7165 79ee a394 12d3 e3b8  .K....qey.......
+00000080: d60b 684b 4193 d116 e180 1e51 e5ba 6d6b  ..hKA......Q..mk
+00000090: eff2 4fab ea68 d097 b531 7c6f d40b 6bc6  ..O..h...1|o..k.
+000000a0: 4735 ffc0 30ce a4c0 140a a02e 648f 775c  G5..0.......d.w\
+000000b0: 1fd1 654d a59e                           ..eM..
diff --git a/src/code/packfiles/2 b/src/code/packfiles/2
new file mode 100644
index 0000000..2ef0476
--- /dev/null
+++ b/src/code/packfiles/2
@@ -0,0 +1,7 @@
+± git rev-list --objects --all | head -1 | \
+  git pack-objects test
+Counting objects: 1, done.
+Total 1 (delta 0), reused 0 (delta 0)
+± ls test-*
+test-ffc030cea4c0140aa02e648f775c1fd1654da59e.idx
+test-ffc030cea4c0140aa02e648f775c1fd1654da59e.pack
diff --git a/src/code/packfiles/3 b/src/code/packfiles/3
new file mode 100644
index 0000000..2381ec5
--- /dev/null
+++ b/src/code/packfiles/3
@@ -0,0 +1,10 @@
+± git gc
+Counting objects: 9, done.
+Delta compression using up to 4 threads.
+Compressing objects: 100% (5/5), done.
+Writing objects: 100% (9/9), done.
+Total 9 (delta 0), reused 0 (delta 0)
+± find .git/objects -type f
+.git/objects/info/packs
+.git/objects/pack/pack-6b3ea4129144c819898dd16a08bc26c62d5ef8cc.idx
+.git/objects/pack/pack-6b3ea4129144c819898dd16a08bc26c62d5ef8cc.pack
diff --git a/src/git-in-reverse.tex b/src/git-in-reverse.tex
index 19e519e..9fee686 100644
--- a/src/git-in-reverse.tex
+++ b/src/git-in-reverse.tex
@@ -43,10 +43,6 @@
 \subtitle{A Backwards Introduction to \\{} the ``information manager from
 hell'' [e83c51633]}
 \author[Ballou]{Kenny Ballou}
-\institute[zData]{%
-    \inst{}%
-    zData, Inc.
-}
 
 \AtBeginSection[]{%
     \begin{frame}
@@ -112,6 +108,9 @@ hell'' [e83c51633]}
 \item<4->{``My preferred VCS tool''}
 \item<5->{The ``information manager from hell''}
 \item<6->{A distributed DAG}
+\begin{itemize}
+\item<6->{``A Graph Tree''}
+\end{itemize}
 \item<7->{An object store}
 \item<8->{A content addressable filesystem}
 \item<9->{A key-value store}
@@ -122,8 +121,8 @@ hell'' [e83c51633]}
 \frametitle{Git±}
 What does Git store?
 \begin{itemize}
-\item<2->{Objects}
-\item<3->{``Packs''}
+\item<2-4>{Objects}
+\item<3-3>{``Packs''}
 \end{itemize}
 \end{frame}
 
@@ -243,7 +242,8 @@ What does Git store?
 \item[100644]{Regular file, *nix permissions 0644}
 \item[100755]{Regular file, *nix permissions 0755, e.g., executable}
 \item[120000]{Symbolic link}
-\item[160000]{?}
+\item[160000]{``Gitlink'', object from another repository, \texttt{fast-import}}
+\item[040000]{Subdirectory, \texttt{fast-import}}
 \end{description}
 \end{frame}
 
@@ -570,6 +570,52 @@ What does Git store?
 \end{figure}
 \end{frame}
 
+\subsection{Packfiles}
+
+\begin{frame}
+\frametitle{Packfiles}
+\begin{itemize}
+\item<2->{Tight Object Storage}
+\item<3->{``Packs'' Objects Together}
+\item<4->{Adds quick, indexed access to objects}
+\item<5->{Motivated for network and access efficiency}
+\begin{itemize}
+\item<5->{Not Disk Space Efficiency}
+\end{itemize}
+\item<6->{Created automatically}
+\end{itemize}
+\end{frame}
+
+\begin{frame}
+\frametitle{Creating Packfiles}
+\begin{itemize}
+\item<1->{\texttt{git-pack-objects}}
+\item<2->{\texttt{git-gc}}
+\end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Creating Packfiles}
+\framesubtitle{\texttt{git-pack-objects}}
+\lstinputlisting[%
+    language=bash,
+    numbers=none,
+    basicstyle=\scriptsize{}\ttfamily{},
+    columns=fixed]{code/packfiles/1}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Creating Packfiles}
+\framesubtitle{\texttt{git-pack-objects}}
+\lstinputlisting[language=bash,numbers=none]{code/packfiles/2}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Creating Packfiles}
+\framesubtitle{\texttt{git-gc}}
+\lstinputlisting[language=bash,numbers=none]{code/packfiles/3}
+\end{frame}
+
 \section{Using Git±}
 \begin{frame}
 \frametitle{Using Git±}
diff --git a/src/references.bib b/src/references.bib
index 11294df..a8df76e 100644
--- a/src/references.bib
+++ b/src/references.bib
@@ -42,3 +42,8 @@
 @misc{website:linus_on_rebase,
     howpublished="\url{http://www.mail-archive.com/dri-devel@lists.sourceforge.net/msg39091.html}"
 }
+@misc{website:unpacking_git_packfiles,
+    howpublished="\url{https://codewords.recurse.com/issues/three/unpacking-git-packfiles/}",
+    author="Aditya Mukerjee",
+    title="Unpacking Git Packfiles"
+}