From cfce31471536ebe42af7d1b7a1958a93beca106c Mon Sep 17 00:00:00 2001
From: Paul Chang <paulchang@google.com>
Date: Fri, 17 May 2024 08:10:26 -0700
Subject: [PATCH] Make BlobWriter::Add() accept const void*

PiperOrigin-RevId: 634780483
---
 compression/blob_store.cc | 9 +++++----
 compression/blob_store.h  | 6 +++---
 2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/compression/blob_store.cc b/compression/blob_store.cc
index 49565d4..47bf00f 100644
--- a/compression/blob_store.cc
+++ b/compression/blob_store.cc
@@ -124,7 +124,7 @@ class BlobStore {
   }
 
   static std::vector<BlobIO> PrepareWriteRequests(
-      const hwy::uint128_t keys[], const hwy::Span<uint8_t> blobs[],
+      const hwy::uint128_t keys[], const hwy::Span<const uint8_t> blobs[],
       size_t num_blobs, BlobStore* bs) {
     // Sanity check and ensure the cast below is safe.
     HWY_ASSERT(num_blobs < (1ULL << 20));
@@ -164,7 +164,8 @@ class BlobStore {
       bs->keys_[num_blobs + i].lo = offset;
       bs->keys_[num_blobs + i].hi = blobs[i].size();
 
-      EnqueueChunkRequests(offset, blobs[i].size(), blobs[i].data(), requests);
+      EnqueueChunkRequests(offset, blobs[i].size(),
+                           const_cast<uint8_t*>(blobs[i].data()), requests);
       offset += blobs[i].size();
       const size_t padded_size = hwy::RoundUpTo(blobs[i].size(), kBlobAlign);
       if (padded_size != blobs[i].size()) {
@@ -270,8 +271,8 @@ BlobError BlobWriter::WriteAll(hwy::ThreadPool& pool, const Path& filename) {
   // Concatenate blobs in memory.
   const size_t header_size = BlobStore::HeaderSize(keys_.size());
   const size_t padded_header_size = hwy::RoundUpTo(header_size, kBlobAlign);
-  BlobStorePtr bs = BlobStore::Allocate(padded_header_size);
-  std::vector<BlobIO> requests = BlobStore::PrepareWriteRequests(
+  const BlobStorePtr bs = BlobStore::Allocate(padded_header_size);
+  const std::vector<BlobIO> requests = BlobStore::PrepareWriteRequests(
       keys_.data(), blobs_.data(), keys_.size(), bs.get());
 
   // Create/replace existing file.
diff --git a/compression/blob_store.h b/compression/blob_store.h
index d95d7e1..119f95c 100644
--- a/compression/blob_store.h
+++ b/compression/blob_store.h
@@ -80,9 +80,9 @@ class BlobReader {
 
 class BlobWriter {
  public:
-  void Add(hwy::uint128_t key, void* data, size_t size) {
+  void Add(hwy::uint128_t key, const void* data, size_t size) {
     keys_.push_back(key);
-    blobs_.emplace_back(static_cast<uint8_t*>(data), size);
+    blobs_.emplace_back(static_cast<const uint8_t*>(data), size);
   }
 
   // Stores all blobs to disk in the given order with padding for alignment.
@@ -90,7 +90,7 @@ class BlobWriter {
 
  private:
   std::vector<hwy::uint128_t> keys_;
-  std::vector<hwy::Span<uint8_t>> blobs_;
+  std::vector<hwy::Span<const uint8_t>> blobs_;
 };
 
 }  // namespace gcpp