Added simple DataSources to replace parts of DataLoader

1 files changed, 166 insertions, 0 deletions

diff --git a/StarsEx/DataSource.cpp b/StarsEx/DataSource.cpp
new file mode 100644
index 0000000..b587971
--- /dev/null
+++ b/StarsEx/DataSource.cpp
@@ -0,0 +1,166 @@
+/*  Starshatter: The Open Source Project
+    Copyright (c) 2021-2022, Starshatter: The Open Source Project Contributors
+    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
+    Copyright (c) 1997-2006, Destroyer Studios LLC.
+*/
+
+#include "DataSource.h"
+
+#include <cstdint>
+#include <cstring>
+#include <filesystem>
+
+#include "Archive.h"
+#include "List.h"
+#include "Text.h"
+
+
+DataSource::DataSource() :
+    m_prefix {""}
+{
+}
+
+
+DataSource::~DataSource()
+{
+}
+
+
+void
+DataSource::SetPrefix(const char* prefix)
+{
+    if (prefix)
+        m_prefix = prefix;
+    else
+        m_prefix = "";
+}
+
+
+ArchiveDataSource::ArchiveDataSource(const char* name) :
+    ArchiveDataSource(new DataArchive(name))
+{
+}
+
+
+ArchiveDataSource::ArchiveDataSource(DataArchive* archive) :
+    m_archive {archive}
+{
+}
+
+
+ArchiveDataSource::~ArchiveDataSource()
+{
+    delete m_archive;
+}
+
+
+bool
+ArchiveDataSource::Find(const char* name) const
+{
+    const int index = m_archive->FindEntry(name);
+    return index > -1;
+}
+
+
+int
+ArchiveDataSource::ListFiles(Text filter, List<Text>& items, bool recurse) const
+{
+    (void) recurse;  // Lookup in DataArchives was always recursive so far
+    filter = filter.replace("*", "");  // Wildcards worked only on boundaries
+    const int prefix = m_prefix.length();
+    const int count = m_archive->NumFiles();
+    for (int i = 0; i < count; ++i) {
+        const auto* entry = m_archive->GetFile(i);
+        Text name = entry->name;
+        name.setSensitive(false);
+        if (name.contains(m_prefix) && name.contains(filter)) {
+            const auto without_prefix = name.substring(prefix, name.length());
+            if (!items.contains(&without_prefix))
+                items.append(new Text(without_prefix));
+        }
+    }
+    return items.size();
+}
+
+
+int
+ArchiveDataSource::Load(const char* name, std::uint8_t*& buf, bool null_terminate) const
+{
+    const int index = m_archive->FindEntry(name);
+    if (index > -1)
+        return m_archive->ExpandEntry(index, buf, null_terminate);
+    return 0;  // -1 would be preferable, but 0 is from legacy
+}
+
+
+FileSystemDataSource::FileSystemDataSource(const char* path) :
+    m_path {path}
+{
+}
+
+
+FileSystemDataSource::~FileSystemDataSource()
+{
+}
+
+
+bool
+FileSystemDataSource::Find(const char* name) const
+{
+    std::filesystem::path full_path {m_path};
+    full_path.append(m_prefix.data());
+    full_path.append(name);
+    return std::filesystem::is_regular_file(full_path);
+}
+
+
+int
+FileSystemDataSource::ListFiles(Text filter, List<Text>& items, bool recurse) const
+{
+    std::filesystem::path full_path {m_path};
+    full_path.append(m_prefix.data());
+    filter = filter.replace("*", "");
+    const auto check = [&items, &filter](const std::filesystem::directory_entry& entry){
+        const auto filename = entry.path().filename().string();
+        const auto index = filename.find(filter.data());
+        if (index != decltype(filename)::npos)
+            items.append(new Text(entry.path().string().c_str()));
+    };
+    if (recurse) {
+        for (const auto& entry : std::filesystem::recursive_directory_iterator(full_path))
+            check(entry);
+    }
+    else {
+        for (const auto& entry : std::filesystem::directory_iterator(full_path))
+            check(entry);
+    }
+    return items.size();
+}
+
+
+int
+FileSystemDataSource::Load(const char* name, std::uint8_t*& buf, bool null_terminate) const
+{
+    std::filesystem::path full_path {m_path};
+    full_path.append(m_prefix.data());
+    full_path.append(name);
+    FILE* f = fopen(full_path.string().c_str(), "rb");
+    if (!f)
+        return 0;  // Again, -1 would be better to differentiate an error from an empty file
+    fseek(f, 0, SEEK_END);
+    int length = ftell(f);
+    fseek(f, 0, SEEK_SET);
+    if (null_terminate) {
+        buf = new std::uint8_t[length + 1];
+        if (buf)
+            buf[length] = 0;
+    }
+    else {
+        buf = new std::uint8_t[length];
+    }
+    int bytes = 0;
+    if (buf)
+        bytes = fread(buf, length, 1, f);
+    fclose(f);
+    return bytes;
+}