From 9c23064839ba5021b199069364dc2001d25d1b0c Mon Sep 17 00:00:00 2001
From: Adrian Sampson <adrian@radbox.org>
Date: Tue, 19 Mar 2024 07:36:25 -0400
Subject: [PATCH] Controllable preallocation

---
 polbin/src/file.rs | 18 +++++++++---------
 polbin/src/main.rs |  6 +++++-
 2 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/polbin/src/file.rs b/polbin/src/file.rs
index 68c5a2a0..07b8023a 100644
--- a/polbin/src/file.rs
+++ b/polbin/src/file.rs
@@ -116,16 +116,16 @@ impl Toc {
         Self {
             magic: MAGIC_NUMBER,
             header: Size::empty(128),
-            segs: Size::empty(512 * factor),
-            paths: Size::empty(16 * factor),
-            links: Size::empty(1024 * factor),
-            steps: Size::empty(512 * factor),
-            seq_data: Size::empty(4096 * factor),
-            overlaps: Size::empty(512 * factor),
-            alignment: Size::empty(1024 * factor),
+            segs: Size::empty(32 * factor * factor),
+            paths: Size::empty(factor),
+            links: Size::empty(32 * factor * factor),
+            steps: Size::empty(1024 * factor * factor),
+            seq_data: Size::empty(512 * factor * factor),
+            overlaps: Size::empty(256 * factor),
+            alignment: Size::empty(64 * factor * factor),
             name_data: Size::empty(64 * factor),
-            optional_data: Size::empty(64 * factor),
-            line_order: Size::empty(2048 * factor),
+            optional_data: Size::empty(512 * factor * factor),
+            line_order: Size::empty(64 * factor * factor),
         }
     }
 }
diff --git a/polbin/src/main.rs b/polbin/src/main.rs
index 6a4463a1..d14f182b 100644
--- a/polbin/src/main.rs
+++ b/polbin/src/main.rs
@@ -65,6 +65,10 @@ struct PolBin {
     /// print statistics about the graph
     #[argh(switch, short = 's')]
     stats: bool,
+
+    /// preallocation size factor
+    #[argh(option, short = 'p', default = "32")]
+    prealloc_factor: usize,
 }
 
 fn main() {
@@ -74,7 +78,7 @@ fn main() {
     if args.mutate {
         if let (None, Some(out_name)) = (&args.input, &args.output) {
             // Create a file with an empty table of contents.
-            let empty_toc = file::Toc::guess(5);
+            let empty_toc = file::Toc::guess(args.prealloc_factor);
             let mut mmap = map_new_file(out_name, empty_toc.size() as u64);
             let (toc, store) = file::init(&mut mmap, empty_toc);