libpressio version 0.33.0

Major Changes

+ Added a noop IO module to make it easier to disable IO
+ Added `supported_metrics()` and `supported_io()` methods to struct pressio for symmetry
+ Added `pressio_supported_metrics()` methods
+ BREAKING CHANGE: pressio_supported_compressors() now returns
  a static string based on what is found in the registry.  While this
  should normally be the consistent with LIBPRESSIO_COMPRESSORS, it
  won't include external compressors.  This change better conforms with
  the documented and intended behavior.

Bug Fixes:

+ The POSIX pressio_io_data_fwrite function now correctly returns the
  number of bytes written as documented.  Previously it returned the
  number of objects written.
+ The POSIX io module now returns error messages on failures
+ the POSIX io module no longer initializes file_ptr to nullptr to avoid
  a bug where it is intentionally set.

CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.13 FATAL_ERROR)
-project(libpressio VERSION "0.32.0" LANGUAGES CXX C)
+project(libpressio VERSION "0.33.0" LANGUAGES CXX C)
 
 #correct was to set a default build type
 # https://blog.kitware.com/cmake-and-the-default-build-type/
@@ -86,6 +86,7 @@ add_library(libpressio
   ./src/plugins/metrics/error_stat.cc
   ./src/plugins/metrics/pearsons.cc
   ./src/plugins/io/posix.cc
+  ./src/plugins/io/noop.cc
   ./src/plugins/io/io.cc
 
   #public headers

include/libpressio_ext/cpp/pressio.h

@@ -194,6 +194,20 @@ struct pressio {
    */
   static const char* supported_compressors();
 
+  /**
+   * \returns the supported metrics list for this version of libpressio
+   *
+   * \see pressio_supported_metrics
+   */
+  static const char* supported_metrics();
+
+  /**
+   * \returns the supported io modules list for this version of libpressio
+   *
+   * \see pressio_supported_io
+   */
+  static const char* supported_io();
+
   /**
    * \returns the major version number of libpressio
    */

src/plugins/io/io.cc

@@ -17,13 +17,7 @@ void pressio_io_free(struct pressio_io* io) {
   delete io;
 }
 const char* pressio_supported_io_modules() {
-  static std::string modules;
-  std::ostringstream os;
-  for (auto const& it : io_plugins()) {
-    os << it.first << " "; 
-  }
-  modules = os.str();
-  return modules.c_str();
+  return pressio::supported_io();
 }
 
 struct pressio_options* pressio_io_get_configuration(struct pressio_io const* io) {

src/plugins/io/noop.cc

@@ -0,0 +1,45 @@
+#include <sys/stat.h>
+#include <unistd.h>
+#include <vector>
+#include "pressio_data.h"
+#include "pressio_compressor.h"
+#include "libpressio_ext/io/posix.h"
+#include "libpressio_ext/cpp/pressio.h"
+#include "libpressio_ext/cpp/options.h"
+#include "libpressio_ext/cpp/data.h"
+#include "libpressio_ext/cpp/io.h"
+
+struct noop_io : public libpressio_io_plugin {
+  virtual struct pressio_data* read_impl(struct pressio_data* data) override {
+    if(data != nullptr) pressio_data_free(data);
+    return nullptr;
+  }
+
+  virtual int write_impl(struct pressio_data const*) override{
+    return 0;
+  }
+  virtual struct pressio_options get_configuration_impl() const override{
+    return {
+      {"pressio:thread_safe",  static_cast<int>(pressio_thread_safety_multiple)}
+    };
+  }
+
+  virtual int set_options_impl(struct pressio_options const&) override{
+    return 0;
+  }
+  virtual struct pressio_options get_options_impl() const override{
+    return {};
+  }
+
+  int patch_version() const override{ 
+    return 1;
+  }
+  virtual const char* version() const override{
+    return "0.0.1";
+  }
+
+  private:
+};
+
+static pressio_register X(io_plugins(), "noop", [](){ return compat::make_unique<noop_io>(); });
+

src/plugins/io/posix.cc

@@ -46,6 +46,7 @@ extern "C" {
   }
 
   struct pressio_data* pressio_io_data_fread(struct pressio_data* dims, FILE* in_file) {
+    if(in_file == nullptr) return nullptr;
     return pressio_io_data_read(dims, fileno(in_file));
   }
 
@@ -68,7 +69,7 @@ extern "C" {
         pressio_dtype_size(pressio_data_dtype(data)),
         pressio_data_num_elements(data),
         out_file
-        );
+        ) * pressio_dtype_size(pressio_data_dtype(data));
   }
 
   size_t pressio_io_data_write(struct pressio_data const* data, int out_filedes) {
@@ -92,18 +93,62 @@ extern "C" {
 
 struct posix_io : public libpressio_io_plugin {
   virtual struct pressio_data* read_impl(struct pressio_data* data) override {
-    if(path) return pressio_io_data_path_read(data, path->c_str());
-    if(file_ptr) return pressio_io_data_fread(data, *file_ptr);
-    if(fd) return pressio_io_data_read(data, *fd);
+    errno = 0;
+    if(path) {
+        auto ret = pressio_io_data_path_read(data, path->c_str());
+        if(ret == nullptr) {
+          if(errno != 0)set_error(2, strerror(errno));
+          else set_error(3, "invalid dims");
+        }
+        return ret;
+    }
+    if(file_ptr) {
+      auto ret = pressio_io_data_fread(data, *file_ptr);
+      if(ret == nullptr) {
+        if(errno != 0)set_error(2, strerror(errno));
+        else set_error(3, "invalid dims");
+      }
+      return ret;
+    }
+    if(fd) {
+      auto ret = pressio_io_data_read(data, *fd);
+      if(ret == nullptr) {
+        if(errno != 0) set_error(2, strerror(errno));
+        else set_error(3, "invalid dims");
+      }
+      return ret;
+    }
 
     invalid_configuration();
     return nullptr;
   }
 
   virtual int write_impl(struct pressio_data const* data) override{
-    if(path) return pressio_io_data_path_write(data, path->c_str()) != data->size_in_bytes();
-    else if(file_ptr) return pressio_io_data_fwrite(data, *file_ptr) != data->size_in_bytes();
-    else if(fd) return pressio_io_data_write(data, *fd) != data->size_in_bytes();
+    errno = 0;
+    if(path) {
+      int ret = pressio_io_data_path_write(data, path->c_str()) != data->size_in_bytes();
+      if(ret) {
+        if(errno) return set_error(2, strerror(errno));
+        else return set_error(3, "unknown failure");
+      }
+      return ret;
+    }
+    else if(file_ptr) {
+      int ret = pressio_io_data_fwrite(data, *file_ptr) != data->size_in_bytes();
+      if(ret) {
+        if(errno) set_error(2, strerror(errno));
+        else set_error(3, "unknown failure");
+      }
+      return ret;
+    }
+    else if(fd) {
+      int ret = pressio_io_data_write(data, *fd) != data->size_in_bytes();
+      if(ret) {
+        if(errno) set_error(2, strerror(errno));
+        else set_error(3, "unknown failure");
+      }
+      return ret;
+    }
     return invalid_configuration();
   }
   virtual struct pressio_options get_configuration_impl() const override{
@@ -163,7 +208,7 @@ struct posix_io : public libpressio_io_plugin {
   }
 
   std::optional<std::string> path;
-  std::optional<FILE*> file_ptr = nullptr;
+  std::optional<FILE*> file_ptr;
   std::optional<int> fd;
 };
 

src/pressio.cc

@@ -2,6 +2,7 @@
 #include <map>
 #include <memory>
 #include <string>
+#include <sstream>
 #include <functional>
 #include "pressio.h"
 #include "pressio_version.h"
@@ -73,6 +74,10 @@ const char* pressio_supported_compressors() {
   return pressio::supported_compressors();
 }
 
+const char* pressio_supported_metrics() {
+  return pressio::supported_metrics();
+}
+
 unsigned int pressio_major_version() {
   return pressio::major_version();
 }
@@ -96,8 +101,28 @@ const char* pressio::features() {
   return LIBPRESSIO_FEATURES;
 }
 
+template <class T>
+static std::string build_from(T const& plugins) {
+  std::ostringstream os;
+  for (auto const& it : plugins) {
+    os << it.first << " "; 
+  }
+  return os.str();
+}
+
 const char* pressio::supported_compressors() {
-  return LIBPRESSIO_COMPRESSORS;
+  static std::string modules = build_from(compressor_plugins());
+  return modules.c_str();
+}
+
+const char* pressio::supported_metrics() {
+  static std::string modules = build_from(metrics_plugins());
+  return modules.c_str();
+}
+
+const char* pressio::supported_io() {
+  static std::string modules = build_from(io_plugins());
+  return modules.c_str();
 }
 
 unsigned int pressio::major_version() {