diff --git a/python/extism/extism.py b/python/extism/extism.py
index b050c4b..6131957 100644
--- a/python/extism/extism.py
+++ b/python/extism/extism.py
@@ -138,11 +138,14 @@ class Plugin:
                 raise Error(ffi.string(error).decode())
             raise Error(f"Error code: {rc}")
 
-    def call(self, name: str, data: Union[str, bytes]) -> bytes:
+    def call(self, name: str, data: Union[str, bytes], parse=bytes) -> bytes:
         if isinstance(data, str):
             data = data.encode()
         self._check_error(
             lib.extism_call(self.plugin, name.encode(), data, len(data)))
         out_len = lib.extism_output_length(self.plugin)
         out_buf = lib.extism_output_get(self.plugin)
-        return ffi.string(out_buf, out_len)
+        buf = ffi.buffer(out_buf, out_len)
+        if parse is None:
+            return buf
+        return parse(buf)
diff --git a/ruby/example.rb b/ruby/example.rb
index 8d880ce..2b509b9 100644
--- a/ruby/example.rb
+++ b/ruby/example.rb
@@ -7,4 +7,3 @@ manifest = {
 plugin = Extism::Plugin.new(manifest)
 res = JSON.parse(plugin.call("count_vowels", ARGV[0] || "this is a test"))
 puts res['count']
-
diff --git a/ruby/lib/extism.rb b/ruby/lib/extism.rb
index 93e0db2..dd88e8b 100644
--- a/ruby/lib/extism.rb
+++ b/ruby/lib/extism.rb
@@ -58,7 +58,9 @@ module Extism
       return ok
     end
 
-    def call(name, data)
+    def call(name, data, &block)
+      # If no block was passed then use Pointer::read_string
+      block ||= ->(buf, len){ buf.read_string(len) }
       input = FFI::MemoryPointer::from_string(data)
       rc = C.extism_call(@plugin, name, input, data.bytesize)
       if rc != 0 then
@@ -70,7 +72,7 @@ module Extism
       end
       out_len = C.extism_output_length(@plugin)
       buf = C.extism_output_get(@plugin)
-      return buf.read_string(out_len)
+      return block.call(buf, out_len)
     end
   end
 end
diff --git a/runtime/src/memory.rs b/runtime/src/memory.rs
index 4a88a8e..096976b 100644
--- a/runtime/src/memory.rs
+++ b/runtime/src/memory.rs
@@ -158,13 +158,13 @@ impl PluginMemory {
             }
         }
 
+        let new_offset = self.position.saturating_add(n);
+
         // If there aren't enough bytes, try to grow the memory size
-        if self.position.saturating_add(n) >= self.size() {
+        if new_offset >= self.size() {
             debug!("Need more memory");
 
-            let bytes_needed = (self.position as f64 + n as f64
-                - self.memory.data_size(&self.store) as f64)
-                / PAGE_SIZE as f64;
+            let bytes_needed = (new_offset as f64 - self.size() as f64) / PAGE_SIZE as f64;
             let mut pages_needed = bytes_needed.ceil() as u64;
             if pages_needed == 0 {
                 pages_needed = 1
@@ -180,6 +180,11 @@ impl PluginMemory {
             length: n,
         };
 
+        info!(
+            "Allocated new block: {} bytes at offset {}",
+            mem.length, mem.offset
+        );
+
         self.live_blocks.insert(mem.offset, mem.length);
         self.position += n;
         Ok(mem)
diff --git a/runtime/src/sdk.rs b/runtime/src/sdk.rs
index fac55ee..e6faa68 100644
--- a/runtime/src/sdk.rs
+++ b/runtime/src/sdk.rs
@@ -218,7 +218,7 @@ pub unsafe extern "C" fn extism_log_file(
             }
         }
     } else {
-        "-"
+        "stderr"
     };
 
     let level = if log_level.is_null() {
@@ -242,18 +242,24 @@ pub unsafe extern "C" fn extism_log_file(
 
     let encoder = Box::new(PatternEncoder::new("{t} {l} {d} - {m}\n"));
 
-    let logfile: Box<dyn log4rs::append::Append> = if file == "-" {
-        let console = ConsoleAppender::builder().encoder(encoder);
-        Box::new(console.build())
-    } else {
-        match FileAppender::builder().encoder(encoder).build(file) {
-            Ok(x) => Box::new(x),
-            Err(e) => {
-                error!("Unable to set up log encoder: {e:?}");
-                return false;
+    let logfile: Box<dyn log4rs::append::Append> =
+        if file == "-" || file == "stdout" || file == "stderr" {
+            let target = if file == "-" || file == "stdout" {
+                log4rs::append::console::Target::Stdout
+            } else {
+                log4rs::append::console::Target::Stderr
+            };
+            let console = ConsoleAppender::builder().target(target).encoder(encoder);
+            Box::new(console.build())
+        } else {
+            match FileAppender::builder().encoder(encoder).build(file) {
+                Ok(x) => Box::new(x),
+                Err(e) => {
+                    error!("Unable to set up log encoder: {e:?}");
+                    return false;
+                }
             }
-        }
-    };
+        };
 
     let config = match Config::builder()
         .appender(Appender::builder().build("logfile", logfile))