Make C++ file io more idiomatic

cplusplus/src/include/utils.hpp

@@ -1,105 +1,68 @@
 #pragma once
-#include <stdlib.h>
+
+#include <cerrno>
+#include <stdexcept>
 #include <stdint.h>
-#include <inttypes.h>
-#include <string.h>
+#include <string>
+#include <sstream>
+#include <fstream>
+
 #ifdef _WIN32
-#include <direct.h>
 #include <windows.h>
 #define PATH_SEPARATOR "\\"
 #else
-#include <libgen.h>
-#include <stdio.h>
 #include <unistd.h>
 #define PATH_SEPARATOR "/"
 #endif
 
-char* get_parent_directory(char* path, const uint32_t levels) {
-#ifdef _WIN32
-    static char drive[_MAX_DRIVE];
-    static char dir[_MAX_DIR];
-    _splitpath(path, drive, dir, NULL, NULL);
-    for (uint32_t i = 0; i < levels; ++i) {
-        size_t len = strlen(dir);
-        if (len > 1 && (dir[len - 1] == '\\' || dir[len - 1] == '/')) {
-            dir[len - 1] = '\0';
-        }
-        char* last_slash = strrchr(dir, '\\');
-        if (!last_slash) last_slash = strrchr(dir, '/');
-        if (last_slash) *last_slash = '\0';
-    }
-    static char parent_dir[_MAX_PATH];
-    snprintf(parent_dir, sizeof(parent_dir), "%s%s", drive, dir);
-    return parent_dir;
-#else
-    char* dir = dirname(path);
+#ifndef MAX_PATH
+#define MAX_PATH 4096
+#endif
+
+std::string get_parent_directory(const std::string &path, const uint32_t levels) {
+    std::string dir = path;
     for (uint32_t i = 0; i < levels; ++i) {
-        dir = dirname(dir);
-        if (strcmp(dir, "/") == 0 || strcmp(dir, ".") == 0) {
+        size_t pos = dir.find_last_of(PATH_SEPARATOR);
+        if (pos != std::string::npos) {
+            dir.erase(pos);
+        } else {
             break;
         }
     }
     return dir;
-#endif
 }
 
-std::string get_data_file(const char *name) {
-    const char* start = __FILE__;
-#ifdef _WIN32
+std::string get_data_file(const std::string &name) {
     char absolute_path[MAX_PATH];
-    if (!_fullpath(absolute_path, start, MAX_PATH)) {
-        perror("_fullpath");
-        return NULL;
+#ifdef _WIN32
+    if (!_fullpath(absolute_path, __FILE__, sizeof(absolute_path))) {
+        std::ostringstream oss;
+        oss << "_fullpath failed with error code " << GetLastError();
+        throw std::runtime_error(oss.str());
     }
 #else
-   char* absolute_path = realpath(start, NULL);
-    if (!absolute_path) {
-        perror("realpath");
-        return NULL;
+    if (!realpath(__FILE__, absolute_path)) {
+        std::ostringstream oss;
+        oss << "realpath failed with error code " << errno;
+        throw std::runtime_error(oss.str());
     }
 #endif
-    char* parents_dir = get_parent_directory(absolute_path, 3);
-    const size_t p_len = strlen(parents_dir),
-    name_len = strlen(name);
-    char *file_path = (char *)malloc(p_len + name_len + 8);
-    memcpy(file_path, parents_dir, p_len);
-    memcpy(file_path + p_len, PATH_SEPARATOR "_data" PATH_SEPARATOR, 7);
-    memcpy(file_path + p_len + 7, name, name_len);
-    file_path[p_len + name_len + 7] = 0;
-    FILE* file = fopen(file_path, "r");
-#ifndef _WIN32
-    free(absolute_path);
-#endif
-//    free(parents_dir);
-    free(file_path);
-    if (!file) {
-        perror("fopen");
-        return NULL;
-    }
 
-    fseek(file, 0, SEEK_END);
-    size_t length = ftell(file);
-    fseek(file, 0, SEEK_SET);
-
-    char* buffer = (char*)malloc(length + 1);
-    if (!buffer) {
-        perror("malloc");
-        fclose(file);
-        return NULL;
+    std::string file_path = get_parent_directory(std::string(absolute_path), 4) + PATH_SEPARATOR "_data" PATH_SEPARATOR + name;
+    std::ifstream file(file_path.c_str(), std::ios::in | std::ios::binary);
+    if (!file) {
+        std::ostringstream oss;
+        oss << "Failed to open file: " << file_path << " with error code " << errno;
+        throw std::runtime_error(oss.str());
     }
 
-    const size_t ret_code = fread(buffer, 1, length, file);
-    if (ret_code != length) {
-        if (feof(file))
-            printf("Error reading %s: unexpected end of file, read %" PRIu64 " of %" PRIu64 " bytes expected\n", name, (uint64_t)ret_code, (uint64_t)length);
-        else if (ferror(file))
-            perror("Error reading data file");
+    std::ostringstream content_stream;
+    content_stream << file.rdbuf();
+    if (!file) {
+        std::ostringstream oss;
+        oss << "Error reading file: " << file_path << " with error code " << errno
+        throw std::runtime_error(oss.str());
     }
 
-    buffer[length] = 0;
-    fclose(file);
-
-    std::string ret(buffer);
-    free(buffer);
-    return ret;
+    return content_stream.str();
 }

docs/conf.py

@@ -227,8 +227,9 @@ def setup(app):
         labels = [lang[0] for lang in langs]
         sizes = [float(lang[1]) for lang in langs]
         counts = [countfiles(lang) for lang in labels]
+        size = max(10, len(labels))
         colormap = plt.get_cmap('tab10' if len(labels) <= 10 else 'tab20')
-        colors = [colormap(idx / len(labels)) for idx, _ in enumerate(labels)]
+        colors = [colormap(idx / size) for idx, _ in enumerate(labels)]
         _, ax = plt.subplots()
         ax.pie(sizes, labels=labels, colors=colors, autopct='%1.1f%%', labeldistance=None, pctdistance=0.85)
         plt.legend(title='Languages', loc='right', bbox_to_anchor=(1,0.5), bbox_transform=plt.gcf().transFigure)

docs/src/cplusplus/lib/macros.rst

@@ -44,6 +44,6 @@ View source code :source:`cplusplus/src/include/macros.hpp`
 
 .. c:namespace-pop::
 
-.. literalinclude:: ../../../../cplusplus/src/include/macros.h
+.. literalinclude:: ../../../../cplusplus/src/include/macros.hpp
    :language: C++
    :linenos:

docs/src/cplusplus/lib/math.rst

@@ -30,6 +30,6 @@ Includes
 
 .. c:namespace-pop::
 
-.. literalinclude:: ../../../../cplusplus/src/include/math.h
+.. literalinclude:: ../../../../cplusplus/src/include/math.hpp
    :language: C++
    :linenos:

docs/src/cplusplus/lib/utils.rst

@@ -5,15 +5,15 @@ View source code :source:`cplusplus/src/include/utils.hpp`
 
 .. cpp:namespace-push:: utils
     
-.. cpp:function:: std::string get_data_file(const char *name)
+.. cpp:function:: std::string get_data_file(const std::string name)
 
     Return a character array containing the whole contents of a file found in _data.
 
-.. cpp:function:: char *get_parent_directory(const char *name, const uint32_t levels)
+.. cpp:function:: std::string get_parent_directory(const std::string &path, uint32_t levels)
 
 .. cpp:namespace-pop::
 
-.. literalinclude:: ../../../../cplusplus/src/include/utils.h
+.. literalinclude:: ../../../../cplusplus/src/include/utils.hpp
    :language: C++
    :linenos: