SERVER-43909 clarify and repair util/hex.h API

 - hexblob namespace
 - Throwy hexblob::decode (nee fromHex)
 - StringData overloads of hex codec ops
 - add unsignedHex<T> and zeroPaddedHex<T>

2 files changed, 8 insertions, 8 deletions

diff --git a/src/mongo/db/pipeline/resume_token.cpp b/src/mongo/db/pipeline/resume_token.cpp
index e6b876769f7..2272bf1d434 100644
--- a/src/mongo/db/pipeline/resume_token.cpp
+++ b/src/mongo/db/pipeline/resume_token.cpp
@@ -119,7 +119,7 @@ ResumeToken::ResumeToken(const ResumeTokenData& data) {
     data.documentKey.addToBsonObj(&builder, "");
     auto keyObj = builder.obj();
     KeyString::Builder encodedToken(KeyString::Version::V1, keyObj, Ordering::make(BSONObj()));
-    _hexKeyString = toHex(encodedToken.getBuffer(), encodedToken.getSize());
+    _hexKeyString = hexblob::encode(encodedToken.getBuffer(), encodedToken.getSize());
     const auto& typeBits = encodedToken.getTypeBits();
     if (!typeBits.isAllZeros())
         _typeBits = Value(
@@ -146,10 +146,10 @@ ResumeTokenData ResumeToken::getData() const {
 
     uassert(ErrorCodes::FailedToParse,
             "resume token string was not a valid hex string",
-            isValidHex(_hexKeyString));
+            hexblob::validate(_hexKeyString));
 
     BufBuilder hexDecodeBuf;  // Keep this in scope until we've decoded the bytes.
-    fromHexString(_hexKeyString, &hexDecodeBuf);
+    hexblob::decode(_hexKeyString, &hexDecodeBuf);
     BSONBinData keyStringBinData =
         BSONBinData(hexDecodeBuf.buf(), hexDecodeBuf.len(), BinDataType::BinDataGeneral);
     auto internalBson = KeyString::toBsonSafe(static_cast<const char*>(keyStringBinData.data),
diff --git a/src/mongo/db/pipeline/resume_token_test.cpp b/src/mongo/db/pipeline/resume_token_test.cpp
index 7f9e5010ab8..88be9cdc940 100644
--- a/src/mongo/db/pipeline/resume_token_test.cpp
+++ b/src/mongo/db/pipeline/resume_token_test.cpp
@@ -160,17 +160,17 @@ TEST(ResumeToken, FailsToDecodeInvalidKeyString) {
     const unsigned char nonsense[] = {165, 85, 77, 86, 255};
 
     // Data of correct type, but empty.
-    const auto emptyToken = ResumeToken::parse(Document{{"_data"_sd, toHex(zeroes, 0)}});
+    const auto emptyToken = ResumeToken::parse(Document{{"_data"_sd, hexblob::encode(zeroes, 0)}});
     ASSERT_THROWS_CODE(emptyToken.getData(), AssertionException, 40649);
 
     // Data of correct type with a bunch of zeros.
     const auto zeroesToken =
-        ResumeToken::parse(Document{{"_data"_sd, toHex(zeroes, sizeof(zeroes))}});
+        ResumeToken::parse(Document{{"_data"_sd, hexblob::encode(zeroes, sizeof(zeroes))}});
     ASSERT_THROWS_CODE(zeroesToken.getData(), AssertionException, 50811);
 
     // Data of correct type with a bunch of nonsense.
     const auto nonsenseToken =
-        ResumeToken::parse(Document{{"_data"_sd, toHex(nonsense, sizeof(nonsense))}});
+        ResumeToken::parse(Document{{"_data"_sd, hexblob::encode(nonsense, sizeof(nonsense))}});
     ASSERT_THROWS_CODE(nonsenseToken.getData(), AssertionException, 50811);
 
     // Valid data, bad typeBits; note that an all-zeros typebits is valid so it is not tested here.
@@ -183,8 +183,8 @@ TEST(ResumeToken, FailsToDecodeInvalidKeyString) {
         60,  // CType::kStringLike
         55,  // Non-null terminated
     };
-    auto invalidStringToken =
-        ResumeToken::parse(Document{{"_data"_sd, toHex(invalidString, sizeof(invalidString))}});
+    auto invalidStringToken = ResumeToken::parse(
+        Document{{"_data"_sd, hexblob::encode(invalidString, sizeof(invalidString))}});
     // invalidStringToken.getData();
     ASSERT_THROWS_WITH_CHECK(
         invalidStringToken.getData(), AssertionException, [](const AssertionException& exception) {