From 26043e6b1d28dc65ae0ea2063d6f8552c4e9a58c Mon Sep 17 00:00:00 2001
From: Olivier Desenfans <desenfans.olivier@gmail.com>
Date: Thu, 23 May 2024 22:29:34 +0200
Subject: [PATCH] feat: load Cairo PIE from bytes (#1773)

* feat: load Cairo PIE from bytes

Context: bootloader support.

Like for programs, it is convenient to be able to load Cairo PIEs directly
from bytes. Added a `from_bytes()` method to `CairoPie`. This method
shares most of its code with `read_from_file()`.

* changelog
---
 CHANGELOG.md                   |  2 ++
 vm/src/vm/runners/cairo_pie.rs | 24 +++++++++++++++++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f8ca0a11c2..c8e35b7f08 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,8 @@
 
 * fix: make MemorySegmentManager.finalize() public [#1771](https://github.com/lambdaclass/cairo-vm/pull/1771)
 
+* feat: load Cairo PIE from bytes [#1773](https://github.com/lambdaclass/cairo-vm/pull/1773)
+
 * feat(BREAKING): Serialize `Array<Felt252>` return value into output segment in cairo1-run crate:
   * Checks that only `PanicResult<Array<Felt252>>` or `Array<Felt252>` can be returned by the program when running with either `--proof_mode` or `--append_return_values`.
   * Serializes return values into the output segment under the previous conditions following the format:
diff --git a/vm/src/vm/runners/cairo_pie.rs b/vm/src/vm/runners/cairo_pie.rs
index 228f4048c6..8c5659e748 100644
--- a/vm/src/vm/runners/cairo_pie.rs
+++ b/vm/src/vm/runners/cairo_pie.rs
@@ -268,12 +268,10 @@ impl CairoPie {
     }
 
     #[cfg(feature = "std")]
-    pub fn read_zip_file(file_path: &Path) -> Result<CairoPie, std::io::Error> {
+    pub fn from_zip_archive<R: std::io::Read + std::io::Seek>(
+        mut zip_reader: zip::ZipArchive<R>,
+    ) -> Result<CairoPie, std::io::Error> {
         use std::io::Read;
-        use zip::ZipArchive;
-
-        let file = File::open(file_path)?;
-        let mut zip_reader = ZipArchive::new(file)?;
 
         let reader = std::io::BufReader::new(zip_reader.by_name("version.json")?);
         let version: CairoPieVersion = serde_json::from_reader(reader)?;
@@ -300,6 +298,22 @@ impl CairoPie {
             version,
         })
     }
+
+    #[cfg(feature = "std")]
+    pub fn from_bytes(bytes: &[u8]) -> Result<Self, std::io::Error> {
+        let reader = std::io::Cursor::new(bytes);
+        let zip_archive = zip::ZipArchive::new(reader)?;
+
+        Self::from_zip_archive(zip_archive)
+    }
+
+    #[cfg(feature = "std")]
+    pub fn read_zip_file(path: &Path) -> Result<Self, std::io::Error> {
+        let file = File::open(path)?;
+        let zip = zip::ZipArchive::new(file)?;
+
+        Self::from_zip_archive(zip)
+    }
 }
 
 pub(super) mod serde_impl {