From c863be8652e5664dc26a88f9f8365b24d0b1908b Mon Sep 17 00:00:00 2001
From: longqm <long2008920@163.com>
Date: Fri, 1 Dec 2023 09:38:51 +0800
Subject: [PATCH] explicit cast uint32 to uint16; add more precise document on
 `rank_many(begin,end,ans)`

---
 include/roaring/containers/array.h | 6 +++---
 include/roaring/roaring.h          | 4 +++-
 src/containers/bitset.c            | 6 +++---
 src/containers/run.c               | 4 ++--
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/include/roaring/containers/array.h b/include/roaring/containers/array.h
index 5603125e4..bf4e4e412 100644
--- a/include/roaring/containers/array.h
+++ b/include/roaring/containers/array.h
@@ -414,15 +414,15 @@ inline int array_container_rank(const array_container_t *arr, uint16_t x) {
 
 // bulk version of array_container_rank(); return number of consumed elements
 inline uint32_t array_container_rank_many(const array_container_t *arr, uint64_t start_rank, const uint32_t* begin, const uint32_t* end, uint64_t* ans){
-    const uint16_t high = (*begin) >> 16;
+    const uint16_t high = (uint16_t)((*begin) >> 16);
     uint32_t pos = 0;
     const uint32_t* iter = begin;
     for(; iter != end; iter++) {
         uint32_t x = *iter;
-        uint16_t xhigh = x >> 16;
+        uint16_t xhigh = (uint16_t)(x >> 16);
         if(xhigh != high) return iter - begin;// stop at next container
 
-        const int32_t idx = binarySearch(arr->array+pos, arr->cardinality-pos, x&0xFFFF);
+        const int32_t idx = binarySearch(arr->array+pos, arr->cardinality-pos, (uint16_t)x);
         const bool is_present = idx >= 0;
         if (is_present) {
             *(ans++) = start_rank + pos + (idx + 1);
diff --git a/include/roaring/roaring.h b/include/roaring/roaring.h
index d82f03da8..d32a08b24 100644
--- a/include/roaring/roaring.h
+++ b/include/roaring/roaring.h
@@ -820,7 +820,9 @@ uint64_t roaring_bitmap_rank(const roaring_bitmap_t *r, uint32_t x);
  * it puts rank value of each element in `[begin .. end)` to `ans[]`
  *
  * the values in `[begin .. end)` must be sorted in Ascending order;
- * the `ans` must have enough size.
+ * Caller is responsible to ensure that there is enough memory allocated, e.g.
+ *
+ *     ans = malloc((end-begin) * sizeof(uint64_t));
  */
 void roaring_bitmap_rank_many(const roaring_bitmap_t *r, const uint32_t* begin, const uint32_t* end, uint64_t* ans);
 
diff --git a/src/containers/bitset.c b/src/containers/bitset.c
index fad229af1..5d38817c4 100644
--- a/src/containers/bitset.c
+++ b/src/containers/bitset.c
@@ -1233,16 +1233,16 @@ int bitset_container_rank(const bitset_container_t *container, uint16_t x) {
 }
 
 uint32_t bitset_container_rank_many(const bitset_container_t *container, uint64_t start_rank, const uint32_t* begin, const uint32_t* end, uint64_t* ans){
-  const uint16_t high = (*begin) >> 16;
+  const uint16_t high = (uint16_t)((*begin) >> 16);
   int i = 0;
   int sum = 0;
   const uint32_t* iter = begin;
   for(; iter != end; iter++) {
       uint32_t x = *iter;
-      uint16_t xhigh = x >> 16;
+      uint16_t xhigh = (uint16_t)(x >> 16);
       if(xhigh != high) return iter - begin; // stop at next container
 
-      uint16_t xlow = x & 0xFFFF;
+      uint16_t xlow = (uint16_t)x;
       for(int count = xlow / 64; i < count; i++){
         sum += roaring_hamming(container->words[i]);
       }
diff --git a/src/containers/run.c b/src/containers/run.c
index b9777cc2f..b3c90b06a 100644
--- a/src/containers/run.c
+++ b/src/containers/run.c
@@ -884,13 +884,13 @@ int run_container_rank(const run_container_t *container, uint16_t x) {
     return sum;
 }
 uint32_t run_container_rank_many(const run_container_t *container, uint64_t start_rank, const uint32_t* begin, const uint32_t* end, uint64_t* ans){
-    const uint16_t high = (*begin) >> 16;
+    const uint16_t high = (uint16_t)((*begin) >> 16);
     const uint32_t* iter = begin;
     int sum = 0;
     int i = 0;
     for(;iter != end; iter++) {
         uint32_t x = *iter;
-        uint16_t xhigh = x >> 16;
+        uint16_t xhigh = (uint16_t)(x >> 16);
         if(xhigh != high) return iter - begin; // stop at next container
 
         uint32_t x32 = x & 0xFFFF;