feat(file): allow case-insensitive file paths to be resolved on Linux

bc/CMakeLists.txt

@@ -3,6 +3,7 @@ file(GLOB BC_SOURCES
     "lock/*.cpp"
     "os/*.cpp"
     "file/*.cpp"
+    "file/path/*.cpp"
     "time/*.cpp"
     "system/*.cpp"
     "system/file/*.cpp"

bc/file/Path.hpp

@@ -1,51 +1 @@
-#ifndef BC_FILE_PATH_HPP
+#include "bc/file/path/Path.hpp"
-#define BC_FILE_PATH_HPP
-
-#include "bc/file/Defines.hpp"
-
-#include <cstddef>
-
-namespace Blizzard {
-namespace File {
-namespace Path {
-
-// Classes
-
-// Quick native path translation on the stack.
-// Can be slow in some instances, as it resorts to heap allocation if path size >= BC_FILE_MAX_PATH
-// Note: this name is an invention, however its behavior is repeated in all System_File implementations.
-// So it probably did exist as an inlined class.
-class QuickNative {
-    private:
-        size_t size;
-        // stack allocation
-        char fastpath[BC_FILE_MAX_PATH];
-        // heap
-        char* fatpath;
-
-    public:
-        QuickNative(const char* path);
-        ~QuickNative();
-        const char* Str();
-        size_t Size();
-};
-
-// Functions
-
-void ForceTrailingSeparator(char* buf, size_t bufMax, char sep);
-
-bool MakeBackslashPath(const char* path, char* result, size_t capacity);
-
-bool MakeConsistentPath(const char* path, char* result, size_t capacity);
-
-bool MakeNativePath(const char* path, char* result, size_t capacity);
-
-bool MakeUnivPath(const char* path, char* result, size_t capacity);
-
-bool MakeWindowsPath(const char* path, char* result, size_t capacity);
-
-} // namespace Path
-} // namespace File
-} // namespace Blizzard
-
-#endif

bc/file/path/Path.cpp

@@ -0,0 +1,225 @@
+#include "bc/file/path/Path.hpp"
+#include "bc/file/path/Posix.hpp"
+#include "bc/String.hpp"
+#include "bc/Memory.hpp"
+#include "bc/Debug.hpp"
+
+#include <cctype>
+
+namespace Blizzard {
+namespace File {
+namespace Path {
+
+// Classes
+
+QuickNative::QuickNative(const char* path) {
+    this->size = 0;
+    this->slowpath = nullptr;
+    this->fastpath[0] = '\0';
+
+    if (!path) {
+        return;
+    }
+
+    // Null byte
+    constexpr size_t reserved = 1;
+
+    this->size = String::Length(path) + reserved;
+
+    char* nativePath = nullptr;
+
+    if (this->size < BC_FILE_MAX_PATH) {
+        // (fast)
+        nativePath = this->fastpath;
+        MakeNativePath(path, this->fastpath, BC_FILE_MAX_PATH);
+    } else {
+        // (slow)
+        this->slowpath = reinterpret_cast<char*>(Memory::Allocate(this->size));
+        nativePath = this->slowpath;
+        MakeNativePath(path, this->slowpath, this->size);
+    }
+
+#if defined(WHOA_SYSTEM_LINUX)
+    // Linux typically does not involve a case-sensitive filesystem
+    // For compatibility, try to find if this path exists in another case
+    // This is much slower
+
+    // The size of the resolved path. Maybe be larger due to "./"
+    size_t resolvedSize = this->size + 2;
+
+    auto resolvedPath = static_cast<char*>(Memory::Allocate(resolvedSize));
+    resolvedPath[resolvedSize-1] = '\0';
+
+    bool wasResolved = ResolvePosixCasePath(nativepath, resolvedPath);
+    if (!wasResolved) {
+        Memory::Free(resolvedPath);
+        return;
+    }
+
+    if (this->slowpath != nullptr) {
+        Memory::Free(this->slowpath);
+    }
+
+    this->slowpath = resolvedPath;
+#endif
+}
+
+QuickNative::~QuickNative() {
+    if (this->slowpath != nullptr) {
+        Memory::Free(this->slowpath);
+    }
+}
+
+const char* QuickNative::Str() {
+    if (this->slowpath != nullptr) {
+        return this->slowpath;
+    }
+
+    return this->fastpath;
+}
+
+size_t QuickNative::Size() {
+    return this->size;
+}
+
+// Functions
+
+void ForceTrailingSeparator(char* buf, size_t bufMax, char sep) {
+    if (buf == nullptr) {
+        return;
+    }
+
+    // If no separator character is provided, infer correct separator based on runes
+    if (sep == '\0') {
+        auto ptr = buf;
+
+        char ch;
+
+        while (true) {
+            ch = *ptr++;
+            // Make inference based on what data we have.
+            if (ch == '/' || ch == '\\') {
+                sep = ch;
+                break;
+            }
+
+            if (ch == '\0') {
+                // Fail safe to the system's path separator.
+                sep = BC_FILE_SYSTEM_PATH_SEPARATOR;
+                break;
+            }
+        }
+    }
+
+    // Buffer needs at least two characters.
+    if (bufMax < 2) {
+        return;
+    }
+
+    // Slice off the end of the path buffer, so that any existing* trailing separator is discarded.
+    auto len = String::Length(buf);
+    char ch = '\0';
+    if (len > 0) {
+        ch = buf[len - 1];
+    }
+    switch (ch) {
+    case '/':
+    case '\\':
+        len--;
+        break;
+    default:
+        break;
+    }
+
+    // Add (back*) trailing separator
+    BLIZZARD_ASSERT(len <= bufMax - 2);
+    buf[len] = sep;
+    buf[len + 1] = '\0'; // pad null
+}
+
+// Convert path to DOS-style.
+// the function will iterate through the path string, converting all occurrences of forward slashes (/) to backslashes (\)
+bool MakeBackslashPath(const char* path, char* result, size_t capacity) {
+    size_t i = 0;
+    size_t c = capacity - 1;
+
+    while (i <= c) {
+        if (path[i] == '\0') {
+            result[i] = '\0';
+            return true;
+        }
+
+        result[i] = path[i] == '/' ? '\\' : path[i];
+
+        i++;
+    }
+
+    result[0] = '\0';
+    return false;
+}
+
+// Make a path string consistent before the last path separator.
+bool MakeConsistentPath(const char* path, char* result, size_t capacity) {
+    if (!result || (capacity < 1)) {
+        return false;
+    }
+
+    if (!path || (capacity == 1)) {
+        *result = '\0';
+        return false;
+    }
+
+    for (auto i = capacity - 1; i != -1; i--) {
+        auto ch = path[i];
+
+        switch (ch) {
+        case '\\':
+            return MakeBackslashPath(path, result, capacity);
+        case '/':
+            return MakeUnivPath(path, result, capacity);
+        case '\0':
+        default:
+            break;
+        }
+    }
+
+    String::Copy(result, path, capacity);
+    return true;
+}
+
+// Convert any path string into something that can be used on the current OS.
+bool MakeNativePath(const char* path, char* result, size_t capacity) {
+#if defined(WHOA_SYSTEM_WIN)
+    return MakeWindowsPath(path, result, capacity);
+#else
+    return MakeUnivPath(path, result, capacity);
+#endif
+}
+
+// Convert a path string into something UNIX-friendly.
+bool MakeUnivPath(const char* path, char* result, size_t capacity) {
+    size_t i = 0; // path and result index
+    size_t c = capacity - 1; // ceiling
+
+    while (i <= c) {
+        if (path[i] == '\0') {
+            result[i] = '\0';
+            return true;
+        }
+
+        result[i] = path[i] == '\\' ? '/' : path[i];
+
+        i++;
+    }
+
+    result[0] = '\0';
+    return false;
+}
+
+bool MakeWindowsPath(const char* path, char* result, size_t capacity) {
+    return MakeBackslashPath(path, result, capacity);
+}
+
+} // namespace Path
+} // namespace File
+} // namespace Blizzard

bc/file/path/Path.hpp

@@ -0,0 +1,51 @@
+#ifndef BC_FILE_PATH_PATH_HPP
+#define BC_FILE_PATH_PATH_HPP
+
+#include "bc/file/Defines.hpp"
+
+#include <cstddef>
+
+namespace Blizzard {
+namespace File {
+namespace Path {
+
+// Classes
+
+// Quick native path translation on the stack.
+// Can be slow in some instances, as it resorts to heap allocation if path size >= BC_FILE_MAX_PATH
+// Note: this name is an invention, however its behavior is repeated in all System_File implementations.
+// So it probably did exist as an inlined class.
+class QuickNative {
+    private:
+        size_t size;
+        // stack allocation
+        char fastpath[BC_FILE_MAX_PATH];
+        // heap
+        char* slowpath;
+
+    public:
+        QuickNative(const char* path);
+        ~QuickNative();
+        const char* Str();
+        size_t Size();
+};
+
+// Functions
+
+void ForceTrailingSeparator(char* buf, size_t bufMax, char sep);
+
+bool MakeBackslashPath(const char* path, char* result, size_t capacity);
+
+bool MakeConsistentPath(const char* path, char* result, size_t capacity);
+
+bool MakeNativePath(const char* path, char* result, size_t capacity);
+
+bool MakeUnivPath(const char* path, char* result, size_t capacity);
+
+bool MakeWindowsPath(const char* path, char* result, size_t capacity);
+
+} // namespace Path
+} // namespace File
+} // namespace Blizzard
+
+#endif

bc/file/path/Posix.cpp

@@ -0,0 +1,75 @@
+#include "bc/file/path/Posix.hpp"
+
+#if defined(WHOA_SYSTEM_LINUX)
+#include <cstring>
+#include <dirent.h>
+#include <alloca.h>
+#include <cstdio>
+#include <cstdint>
+
+// adapted from https://github.com/OneSadCookie/fcaseopen/blob/master/fcaseopen.c
+bool ResolvePosixCasePath(const char* path, char* r) {
+    auto l = strlen(path);
+    auto p = static_cast<char*>(alloca(l + 1));
+    strcpy(p, path);
+    size_t rl = 0;
+
+    DIR* d;
+    if (p[0] == '/') {
+        d = opendir("/");
+        p = p + 1;
+    } else {
+        d = opendir(".");
+        r[0] = '.';
+        r[1] = 0;
+        rl = 1;
+    }
+
+    int32_t last = 0;
+    auto c = strsep(&p, "/");
+    while (c) {
+        if (!d) {
+            return false;
+        }
+
+        if (last) {
+            closedir(d);
+            return false;
+        }
+
+        r[rl] = '/';
+        rl += 1;
+        r[rl] = 0;
+
+        struct dirent* e = readdir(d);
+        while (e) {
+            if (strcasecmp(c, e->d_name) == 0) {
+                strcpy(r + rl, e->d_name);
+                rl += strlen(e->d_name);
+
+                closedir(d);
+                d = opendir(r);
+
+                break;
+            }
+
+            e = readdir(d);
+        }
+
+        if (!e) {
+            strcpy(r + rl, c);
+            rl += strlen(c);
+            last = 1;
+        }
+
+        c = strsep(&p, "/");
+    }
+
+    if (d) {
+        closedir(d);
+    }
+
+    return true;
+}
+
+#endif

bc/file/path/Posix.hpp

@@ -0,0 +1,6 @@
+#ifndef BC_FILE_PATH_POSIX_HPP
+#define BC_FILE_PATH_POSIX_HPP
+
+bool ResolvePosixCasePath(const char* path, char* r);
+
+#endif