Replace assert_internal::GetStreamable() with public `riegeli::Debu…

…g()`,

extensible using `RiegeliDebug()` FTADLE.

Use it for printing of values under an assertion and to replace quoted
`absl::CHexEscape()`.

Extract some operations on `std::ostream` to `stream_utils.h`.

PiperOrigin-RevId: 693716729

riegeli/base/BUILD

@@ -41,6 +41,31 @@ cc_library(
     ],
 )
 
+cc_library(
+    name = "stream_utils",
+    srcs = ["stream_utils.cc"],
+    hdrs = ["stream_utils.h"],
+    deps = [
+        "@com_google_absl//absl/base:core_headers",
+        "@com_google_absl//absl/strings",
+    ],
+)
+
+cc_library(
+    name = "debug",
+    srcs = ["debug.cc"],
+    hdrs = ["debug.h"],
+    deps = [
+        ":stream_utils",
+        "@com_google_absl//absl/base:core_headers",
+        "@com_google_absl//absl/meta:type_traits",
+        "@com_google_absl//absl/strings",
+        "@com_google_absl//absl/strings:cord",
+        "@com_google_absl//absl/types:optional",
+        "@com_google_absl//absl/types:span",
+    ],
+)
+
 cc_library(
     name = "assert",
     srcs = [
@@ -49,6 +74,7 @@ cc_library(
     ],
     hdrs = ["assert.h"],
     deps = [
+        ":debug",
         "@com_google_absl//absl/base:core_headers",
     ],
 )
@@ -466,6 +492,7 @@ cc_library(
         ":memory_estimator",
         ":new_aligned",
         ":shared_ptr",
+        ":stream_utils",
         ":string_utils",
         ":to_string_view",
         "@com_google_absl//absl/base:core_headers",

riegeli/base/assert.h

@@ -16,7 +16,6 @@
 #define RIEGELI_BASE_ASSERT_H_
 
 #include <stddef.h>
-#include <stdint.h>
 
 #include <ostream>  // IWYU pragma: export
 #include <sstream>
@@ -25,6 +24,7 @@
 
 #include "absl/base/attributes.h"
 #include "absl/base/optimization.h"
+#include "riegeli/base/debug.h"
 #include "riegeli/base/port.h"
 
 namespace riegeli {
@@ -95,30 +95,11 @@ class CheckResult {
   const char* message_ = nullptr;
 };
 
-// For showing a value in a failure message involving a comparison, if needed
-// then converts the value to a different type with the appropriate behavior of
-// `operator<<`: characters are shown as integers.
-
-inline int GetStreamable(char value) { return value; }
-inline int GetStreamable(signed char value) { return value; }
-inline unsigned GetStreamable(unsigned char value) { return value; }
-inline int GetStreamable(wchar_t value) { return value; }
-#if __cpp_char8_t
-inline unsigned GetStreamable(char8_t value) { return value; }
-#endif
-inline uint16_t GetStreamable(char16_t value) { return value; }
-inline uint32_t GetStreamable(char32_t value) { return value; }
-
-template <typename T>
-inline const T& GetStreamable(const T& value) {
-  return value;
-}
-
 template <typename A, typename B>
 ABSL_ATTRIBUTE_COLD const char* FormatCheckOpMessage(const char* message,
                                                      const A& a, const B& b) {
   std::ostringstream stream;
-  stream << message << " (" << GetStreamable(a) << " vs. " << GetStreamable(b)
+  stream << message << " (" << riegeli::Debug(a) << " vs. " << riegeli::Debug(b)
          << ")";
   // Do not bother with freeing this string: the program will soon terminate.
   return (new std::string(stream.str()))->c_str();

riegeli/base/chain.cc

@@ -44,6 +44,7 @@
 #include "riegeli/base/memory_estimator.h"
 #include "riegeli/base/new_aligned.h"
 #include "riegeli/base/ownership.h"
+#include "riegeli/base/stream_utils.h"
 #include "riegeli/base/string_utils.h"
 
 namespace riegeli {
@@ -62,16 +63,6 @@ constexpr Chain::BlockPtrPtr Chain::BlockIterator::kEndShortData;
 
 namespace {
 
-void WritePadding(std::ostream& dest, size_t length) {
-  char buffer[64];
-  std::memset(buffer, dest.fill(), sizeof(buffer));
-  while (length > sizeof(buffer)) {
-    dest.write(buffer, std::streamsize{sizeof(buffer)});
-    length -= sizeof(buffer);
-  }
-  dest.write(buffer, IntCast<std::streamsize>(length));
-}
-
 // Stores an `absl::Cord` which must be flat, i.e.
 // `src.TryFlat() != absl::nullopt`.
 //
@@ -2112,25 +2103,11 @@ StrongOrdering Chain::Compare(const Chain& a, absl::string_view b) {
 }
 
 void Chain::Output(std::ostream& dest) const {
-  std::ostream::sentry sentry(dest);
-  if (sentry) {
-    size_t left_pad = 0;
-    size_t right_pad = 0;
-    if (IntCast<size_t>(dest.width()) > size()) {
-      const size_t pad = IntCast<size_t>(dest.width()) - size();
-      if ((dest.flags() & dest.adjustfield) == dest.left) {
-        right_pad = pad;
-      } else {
-        left_pad = pad;
-      }
-    }
-    if (left_pad > 0) WritePadding(dest, left_pad);
+  WriteWithPadding(dest, size(), [&] {
     for (const absl::string_view fragment : blocks()) {
       dest.write(fragment.data(), IntCast<std::streamsize>(fragment.size()));
     }
-    if (right_pad > 0) WritePadding(dest, right_pad);
-    dest.width(0);
-  }
+  });
 }
 
 void Chain::VerifyInvariants() const {

riegeli/base/chain_base.h

@@ -418,6 +418,12 @@ class Chain : public WithCompare<Chain> {
     return dest;
   }
 
+  // Support `riegeli::Debug()`.
+  template <typename DebugStream>
+  friend void RiegeliDebug(const Chain& src, DebugStream& dest) {
+    src.Debug(dest);
+  }
+
   // Support `absl::Format(&chain, format, args...)`.
   friend void AbslFormatFlush(Chain* dest, absl::string_view src) {
     dest->Append(src);
@@ -594,6 +600,8 @@ class Chain : public WithCompare<Chain> {
   template <typename Sink>
   void Stringify(Sink& dest) const;
   void Output(std::ostream& dest) const;
+  template <typename DebugStream>
+  void Debug(DebugStream& dest) const;
 
   BlockPtrs block_ptrs_;
 

riegeli/base/chain_details.h

@@ -1256,6 +1256,16 @@ void Chain::Stringify(Sink& dest) const {
   for (const absl::string_view block : blocks()) dest.Append(block);
 }
 
+template <typename DebugStream>
+void Chain::Debug(DebugStream& dest) const {
+  dest.DebugStringQuote();
+  typename DebugStream::EscapeState escape_state;
+  for (const absl::string_view fragment : blocks()) {
+    dest.DebugStringFragment(fragment, escape_state);
+  }
+  dest.DebugStringQuote();
+}
+
 }  // namespace riegeli
 
 #endif  // RIEGELI_BASE_CHAIN_DETAILS_H_