From d295828545b6671945d159f4806712051649b2dd Mon Sep 17 00:00:00 2001
From: Sandu Liviu Catalin <slc.proxy@gmail.com>
Date: Sun, 5 Mar 2023 15:37:24 +0200
Subject: [PATCH] Add GetJSON method to buffer.

---
 module/Library/IO/Buffer.cpp | 28 ++++++++++++++++++++++++++++
 module/Library/IO/Buffer.hpp |  6 ++++++
 module/Library/JSON.cpp      | 16 ++++++++++++++++
 3 files changed, 50 insertions(+)

diff --git a/module/Library/IO/Buffer.cpp b/module/Library/IO/Buffer.cpp
index 5a9a5444..d6acf198 100644
--- a/module/Library/IO/Buffer.cpp
+++ b/module/Library/IO/Buffer.cpp
@@ -351,6 +351,33 @@ Vector4 SqBuffer::ReadVector4() const
     return {value};
 }
 
+// ------------------------------------------------------------------------------------------------
+extern SQInteger SqFromNativeJSON(HSQUIRRELVM vm, const char * data, size_t size);
+
+// ------------------------------------------------------------------------------------------------
+SQInteger SqBuffer::GetJSON(HSQUIRRELVM vm) const
+{
+    // Remember the current stack size
+    const SQInteger top = sq_gettop(vm);
+    // Was the JSON string size specified?
+    if (top < 2)
+    {
+        return sq_throwerror(vm, _SC("Please specify the size of the JSON string to parse"));
+    }
+    // Do we even point to a valid buffer?
+    if (!m_Buffer)
+    {
+        return sq_throwerror(vm, _SC("Invalid memory buffer reference"));
+    }
+    // Validate the buffer itself
+    else if (!(*m_Buffer))
+    {
+        return sq_throwerror(vm, _SC("Invalid memory buffer"));
+    }
+    // Attempt to create the JSON object and push it on the stack
+    return SqFromNativeJSON(vm, &m_Buffer->Cursor< char >(), static_cast< size_t >(Var< SQInteger >{vm, 2}.value));
+}
+
 // ------------------------------------------------------------------------------------------------
 SQInteger SqBuffer::GetCRC32(SQInteger n) const
 {
@@ -500,6 +527,7 @@ void Register_Buffer(HSQUIRRELVM vm)
         .Func(_SC("ADLER32"), &SqBuffer::GetADLER32)
         .Func(_SC("Base32"), &SqBuffer::GetBase32)
         .Func(_SC("Base64"), &SqBuffer::GetBase64)
+        .SquirrelMethod< SqBuffer, &SqBuffer::GetJSON >(_SC("GetJSON"))
     );
 }
 
diff --git a/module/Library/IO/Buffer.hpp b/module/Library/IO/Buffer.hpp
index bee88590..c7a4e0a6 100644
--- a/module/Library/IO/Buffer.hpp
+++ b/module/Library/IO/Buffer.hpp
@@ -782,6 +782,12 @@ public:
     */
     SQMOD_NODISCARD Vector4 ReadVector4() const;
 
+    /* --------------------------------------------------------------------------------------------
+     * Transform a portion of the data in the buffer to a JSON object.
+     * This has the benefit that a temporary string doesn't have to be created.
+    */
+    SQMOD_NODISCARD SQInteger GetJSON(HSQUIRRELVM vm) const;
+
     /* --------------------------------------------------------------------------------------------
      * Compute the CRC-32 checksums on the data in the buffer.
     */
diff --git a/module/Library/JSON.cpp b/module/Library/JSON.cpp
index aaeedfea..5d4f98ff 100644
--- a/module/Library/JSON.cpp
+++ b/module/Library/JSON.cpp
@@ -149,6 +149,22 @@ static SQInteger SqFromJSON(HSQUIRRELVM vm) noexcept
     return SQ_SUCCEEDED(r) ? 1 : r;
 }
 
+// ------------------------------------------------------------------------------------------------
+SQInteger SqFromNativeJSON(HSQUIRRELVM vm, const char * data, size_t size)
+{
+    // Attempt to parse the specified JSON string
+    const sajson::document & document = sajson::parse(sajson::dynamic_allocation(), sajson::string(data, size));
+    // See if there was an error
+    if (!document.is_valid())
+    {
+        return sq_throwerror(vm, document.get_error_message_as_cstring());
+    }
+    // Process the nodes that were parsed from the string
+    SQInteger r = SqFromJson_Push(vm, document.get_root());
+    // We either have a value to return or we propagate some error
+    return SQ_SUCCEEDED(r) ? 1 : r;
+}
+
 // ------------------------------------------------------------------------------------------------
 CtxJSON & CtxJSON::OpenArray()
 {