Merge #19326: Simplify hash.h interface using Spans

77c507358bda9bd6c496f33e0f4418c0603bb08d Make Hash[160] consume range-like objects (Pieter Wuille)
02c4cc5c5ddf61f98ee366a4bea8abc26de492bd Make CHash256/CHash160 output to Span (Pieter Wuille)
0ef97b1b103231db54e04a64bbdb5dcc3f34f482 Make MurmurHash3 consume Spans (Pieter Wuille)
e549bf8a9afae42fcda805e216a1cde62df195a6 Make CHash256 and CHash160 consume Spans (Pieter Wuille)
2a2182c387f607cd8284f33890bd285a81077b7f Make script/standard's BaseHash Span-convertible (Pieter Wuille)
e63dcc3a6752e7d406e7a650c2d6c2e95cd39aab Add MakeUCharSpan, to help constructing Span<[const] unsigned char> (Pieter Wuille)
567825049fb0e47e698dcaad9caa65693a6b42d3 Make uint256 Span-convertible by adding ::data() (Pieter Wuille)
131a2f0337f5c396739a47b60bb856ed84ec8937 scripted-diff: rename base_blob::data to m_data (Pieter Wuille)

Pull request description:

  This makes use of the implicit constructions and conversions to Span introduced in #18468 to simplify the hash.h interface:

  * All functions that take a pointer and a length are changed to take a Span instead.
  * The Hash() and Hash160() functions are changed to take in "range" objects instead of begin/end iterators.

ACKs for top commit:
  laanwj:
    re-ACK 77c507358bda9bd6c496f33e0f4418c0603bb08d
  jonatack:
    Code review re-ACK 77c5073 per `git range-diff 14ceddd 49fc016 77c5073`

Tree-SHA512: 9ec929891b1ddcf30eb14b946ee1bf142eca1442b9de0067ad6a3c181e0c7ea0c99c0e291e7f6e7a18bd7bdf78fe94ee3d5de66e167401674caf91e026269771

1 files changed, 20 insertions, 39 deletions

diff --git a/src/hash.h b/src/hash.h
index c295568a3e..71806483ff 100644
--- a/src/hash.h
+++ b/src/hash.h
@@ -25,14 +25,15 @@ private:
 public:
     static const size_t OUTPUT_SIZE = CSHA256::OUTPUT_SIZE;
 
-    void Finalize(unsigned char hash[OUTPUT_SIZE]) {
+    void Finalize(Span<unsigned char> output) {
+        assert(output.size() == OUTPUT_SIZE);
         unsigned char buf[CSHA256::OUTPUT_SIZE];
         sha.Finalize(buf);
-        sha.Reset().Write(buf, CSHA256::OUTPUT_SIZE).Finalize(hash);
+        sha.Reset().Write(buf, CSHA256::OUTPUT_SIZE).Finalize(output.data());
     }
 
-    CHash256& Write(const unsigned char *data, size_t len) {
-        sha.Write(data, len);
+    CHash256& Write(Span<const unsigned char> input) {
+        sha.Write(input.data(), input.size());
         return *this;
     }
 
@@ -49,14 +50,15 @@ private:
 public:
     static const size_t OUTPUT_SIZE = CRIPEMD160::OUTPUT_SIZE;
 
-    void Finalize(unsigned char hash[OUTPUT_SIZE]) {
+    void Finalize(Span<unsigned char> output) {
+        assert(output.size() == OUTPUT_SIZE);
         unsigned char buf[CSHA256::OUTPUT_SIZE];
         sha.Finalize(buf);
-        CRIPEMD160().Write(buf, CSHA256::OUTPUT_SIZE).Finalize(hash);
+        CRIPEMD160().Write(buf, CSHA256::OUTPUT_SIZE).Finalize(output.data());
     }
 
-    CHash160& Write(const unsigned char *data, size_t len) {
-        sha.Write(data, len);
+    CHash160& Write(Span<const unsigned char> input) {
+        sha.Write(input.data(), input.size());
         return *this;
     }
 
@@ -67,52 +69,31 @@ public:
 };
 
 /** Compute the 256-bit hash of an object. */
-template<typename T1>
-inline uint256 Hash(const T1 pbegin, const T1 pend)
+template<typename T>
+inline uint256 Hash(const T& in1)
 {
-    static const unsigned char pblank[1] = {};
     uint256 result;
-    CHash256().Write(pbegin == pend ? pblank : (const unsigned char*)&pbegin[0], (pend - pbegin) * sizeof(pbegin[0]))
-              .Finalize((unsigned char*)&result);
+    CHash256().Write(MakeUCharSpan(in1)).Finalize(result);
     return result;
 }
 
 /** Compute the 256-bit hash of the concatenation of two objects. */
 template<typename T1, typename T2>
-inline uint256 Hash(const T1 p1begin, const T1 p1end,
-                    const T2 p2begin, const T2 p2end) {
-    static const unsigned char pblank[1] = {};
+inline uint256 Hash(const T1& in1, const T2& in2) {
     uint256 result;
-    CHash256().Write(p1begin == p1end ? pblank : (const unsigned char*)&p1begin[0], (p1end - p1begin) * sizeof(p1begin[0]))
-              .Write(p2begin == p2end ? pblank : (const unsigned char*)&p2begin[0], (p2end - p2begin) * sizeof(p2begin[0]))
-              .Finalize((unsigned char*)&result);
+    CHash256().Write(MakeUCharSpan(in1)).Write(MakeUCharSpan(in2)).Finalize(result);
     return result;
 }
 
 /** Compute the 160-bit hash an object. */
 template<typename T1>
-inline uint160 Hash160(const T1 pbegin, const T1 pend)
+inline uint160 Hash160(const T1& in1)
 {
-    static unsigned char pblank[1] = {};
     uint160 result;
-    CHash160().Write(pbegin == pend ? pblank : (const unsigned char*)&pbegin[0], (pend - pbegin) * sizeof(pbegin[0]))
-              .Finalize((unsigned char*)&result);
+    CHash160().Write(MakeUCharSpan(in1)).Finalize(result);
     return result;
 }
 
-/** Compute the 160-bit hash of a vector. */
-inline uint160 Hash160(const std::vector<unsigned char>& vch)
-{
-    return Hash160(vch.begin(), vch.end());
-}
-
-/** Compute the 160-bit hash of a vector. */
-template<unsigned int N>
-inline uint160 Hash160(const prevector<N, unsigned char>& vch)
-{
-    return Hash160(vch.begin(), vch.end());
-}
-
 /** A writer stream (for serialization) that computes a 256-bit hash. */
 class CHashWriter
 {
@@ -129,13 +110,13 @@ public:
     int GetVersion() const { return nVersion; }
 
     void write(const char *pch, size_t size) {
-        ctx.Write((const unsigned char*)pch, size);
+        ctx.Write({(const unsigned char*)pch, size});
     }
 
     // invalidates the object
     uint256 GetHash() {
         uint256 result;
-        ctx.Finalize((unsigned char*)&result);
+        ctx.Finalize(result);
         return result;
     }
 
@@ -200,7 +181,7 @@ uint256 SerializeHash(const T& obj, int nType=SER_GETHASH, int nVersion=PROTOCOL
     return ss.GetHash();
 }
 
-unsigned int MurmurHash3(unsigned int nHashSeed, const std::vector<unsigned char>& vDataToHash);
+unsigned int MurmurHash3(unsigned int nHashSeed, Span<const unsigned char> vDataToHash);
 
 void BIP32Hash(const ChainCode &chainCode, unsigned int nChild, unsigned char header, const unsigned char data[32], unsigned char output[64]);