Add a FileManager and File class

1 files changed, 173 insertions, 0 deletions

diff --git a/src/filemanager.cpp b/src/filemanager.cpp
new file mode 100644
index 00000000..b6164519
--- /dev/null
+++ b/src/filemanager.cpp
@@ -0,0 +1,173 @@
+/******************************************************************************
+ * Project:  PROJ
+ * Purpose:  File manager
+ * Author:   Even Rouault, <even.rouault at spatialys.com>
+ *
+ ******************************************************************************
+ * Copyright (c) 2019, Even Rouault, <even.rouault at spatialys.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *****************************************************************************/
+
+#include "filemanager.hpp"
+#include "proj_internal.h"
+
+NS_PROJ_START
+
+// ---------------------------------------------------------------------------
+
+File::File() = default;
+
+// ---------------------------------------------------------------------------
+
+File::~File() = default;
+
+// ---------------------------------------------------------------------------
+
+class FileStdio : public File {
+    PJ_CONTEXT *m_ctx;
+    FILE *m_fp;
+
+    FileStdio(const FileStdio &) = delete;
+    FileStdio &operator=(const FileStdio &) = delete;
+
+  protected:
+    FileStdio(PJ_CONTEXT *ctx, FILE *fp) : m_ctx(ctx), m_fp(fp) {}
+
+  public:
+    ~FileStdio() override;
+
+    size_t read(void *buffer, size_t sizeBytes) override;
+    bool seek(unsigned long long offset, int whence = SEEK_SET) override;
+    unsigned long long tell() override;
+
+    static std::unique_ptr<File> open(PJ_CONTEXT *ctx, const char *filename);
+};
+
+// ---------------------------------------------------------------------------
+
+FileStdio::~FileStdio() { fclose(m_fp); }
+
+// ---------------------------------------------------------------------------
+
+size_t FileStdio::read(void *buffer, size_t sizeBytes) {
+    return fread(buffer, 1, sizeBytes, m_fp);
+}
+
+// ---------------------------------------------------------------------------
+
+bool FileStdio::seek(unsigned long long offset, int whence) {
+    // TODO one day: use 64-bit offset compatible API
+    if (offset != static_cast<unsigned long long>(static_cast<long>(offset))) {
+        pj_log(m_ctx, PJ_LOG_ERROR,
+               "Attempt at seeking to a 64 bit offset. Not supported yet");
+        return false;
+    }
+    return fseek(m_fp, static_cast<long>(offset), whence) == 0;
+}
+
+// ---------------------------------------------------------------------------
+
+unsigned long long FileStdio::tell() {
+    // TODO one day: use 64-bit offset compatible API
+    return ftell(m_fp);
+}
+
+// ---------------------------------------------------------------------------
+
+std::unique_ptr<File> FileStdio::open(PJ_CONTEXT *ctx, const char *filename) {
+    auto fp = fopen(filename, "rb");
+    return std::unique_ptr<File>(fp ? new FileStdio(ctx, fp) : nullptr);
+}
+
+// ---------------------------------------------------------------------------
+
+#ifndef REMOVE_LEGACY_SUPPORT
+
+class FileLegacyAdapter : public File {
+    PJ_CONTEXT *m_ctx;
+    PAFile m_fp;
+
+    FileLegacyAdapter(const FileLegacyAdapter &) = delete;
+    FileLegacyAdapter &operator=(const FileLegacyAdapter &) = delete;
+
+  protected:
+    FileLegacyAdapter(PJ_CONTEXT *ctx, PAFile fp) : m_ctx(ctx), m_fp(fp) {}
+
+  public:
+    ~FileLegacyAdapter() override;
+
+    size_t read(void *buffer, size_t sizeBytes) override;
+    bool seek(unsigned long long offset, int whence = SEEK_SET) override;
+    unsigned long long tell() override;
+
+    static std::unique_ptr<File> open(PJ_CONTEXT *ctx, const char *filename);
+};
+
+// ---------------------------------------------------------------------------
+
+FileLegacyAdapter::~FileLegacyAdapter() { pj_ctx_fclose(m_ctx, m_fp); }
+
+// ---------------------------------------------------------------------------
+
+size_t FileLegacyAdapter::read(void *buffer, size_t sizeBytes) {
+    return pj_ctx_fread(m_ctx, buffer, 1, sizeBytes, m_fp);
+}
+
+// ---------------------------------------------------------------------------
+
+bool FileLegacyAdapter::seek(unsigned long long offset, int whence) {
+    if (offset != static_cast<unsigned long long>(static_cast<long>(offset))) {
+        pj_log(m_ctx, PJ_LOG_ERROR,
+               "Attempt at seeking to a 64 bit offset. Not supported yet");
+        return false;
+    }
+    return pj_ctx_fseek(m_ctx, m_fp, static_cast<long>(offset), whence) == 0;
+}
+
+// ---------------------------------------------------------------------------
+
+unsigned long long FileLegacyAdapter::tell() {
+    return pj_ctx_ftell(m_ctx, m_fp);
+}
+
+// ---------------------------------------------------------------------------
+
+std::unique_ptr<File> FileLegacyAdapter::open(PJ_CONTEXT *ctx,
+                                              const char *filename) {
+    auto fid = pj_ctx_fopen(ctx, filename, "rb");
+    return std::unique_ptr<File>(fid ? new FileLegacyAdapter(ctx, fid)
+                                     : nullptr);
+}
+
+#endif // REMOVE_LEGACY_SUPPORT
+
+// ---------------------------------------------------------------------------
+
+std::unique_ptr<File> FileManager::open(PJ_CONTEXT *ctx, const char *filename) {
+#ifndef REMOVE_LEGACY_SUPPORT
+    // If the user has specified a legacy fileapi, use it
+    if (ctx->fileapi_legacy != pj_get_default_fileapi()) {
+        return FileLegacyAdapter::open(ctx, filename);
+    }
+#endif
+    return FileStdio::open(ctx, filename);
+}
+
+NS_PROJ_END