rewrite file system layer

1 files changed, 0 insertions, 296 deletions

diff --git a/kernel/fs/tarfs.cpp b/kernel/fs/tarfs.cpp
deleted file mode 100644
index 7508c03..0000000
--- a/kernel/fs/tarfs.cpp
+++ /dev/null
@@ -1,296 +0,0 @@
-#include <mercury/kernel/fs/tarfs.hpp>
-
-//in fs::tarfs_instance, storage::node_id_t refers to the number
-//of bytes into the block device that the info sector is located
-
-namespace mercury::kernel::fs {
-
-  storage::io_result tarfs_mounter(
-    storage::block_device *bd, storage::file_system_instance *&fs_out
-  ) {
-    fs_out = new tarfs_instance(bd);
-    return storage::io_result::success;
-  }
-
-  tarfs_instance::tarfs_instance(storage::block_device *bd) : bd(bd) {}
-
-  storage::io_result tarfs_instance::next_node(storage::node_id_t &node) {
-    uint64_t file_length;
-    storage::io_result result = read_num(node + 124, 12, file_length);
-    if (result != storage::io_result::success)
-      return result;
-    node += ((file_length - 1) / 512 + 2) * 512;
-    uint8_t sector[512];
-    result = bd->read_bytes(node, 512, sector);
-    if (result != storage::io_result::success)
-      return result;
-    for (unsigned i = 0; i < 512; ++i)
-      if (sector[i] != 0)
-        return storage::io_result::success;
-    return storage::io_result::out_of_bounds;
-  }
-
-  storage::io_result tarfs_instance::read_name(
-    storage::node_id_t node, char *name_buf, unsigned &name_len_out
-  ) {
-    name_len_out = 0;
-    storage::io_result result = bd->read_bytes(node + 345, 155, name_buf);
-    if (result != storage::io_result::success)
-      return result;
-    while (name_buf[name_len_out] && name_len_out < 155)
-      ++name_len_out;
-    result = bd->read_bytes(node, 100, name_buf + name_len_out);
-    if (result != storage::io_result::success)
-      return result;
-    unsigned new_limit = name_len_out + 100;
-    while (name_buf[name_len_out] && name_len_out < new_limit)
-      ++name_len_out;
-    return storage::io_result::success;
-  }
-
-  storage::io_result tarfs_instance::read_num(
-    uint64_t offset, unsigned len, uint64_t &out
-  ) {
-
-    //len <= 12
-    char buffer[12];
-    storage::io_result result = bd->read_bytes(offset, len, buffer);
-    if (result != storage::io_result::success)
-      return result;
-    out = 0;
-
-    for (unsigned i = 0; i < len; ++i) {
-      if (!buffer[i])
-        return i == 0 ? storage::io_result::fs_corrupt
-                      : storage::io_result::success;
-      if (buffer[i] < '0' || buffer[i] > '7')
-        return storage::io_result::fs_corrupt;
-      out = out * 8 + buffer[i] - '0';
-    }
-
-    return storage::io_result::success;
-
-  }
-
-#define RETURN_MAYBE_NOT_FOUND(expr) \
-  { \
-    storage::io_result _result = expr; \
-    if (_result == storage::io_result::out_of_bounds) \
-      return storage::io_result::not_found; \
-    if (_result != storage::io_result::success) \
-      return _result; \
-  }
-
-#define RETURN_NOT_SUCCESS(expr) \
-  { \
-    storage::io_result _result = expr; \
-    if (_result != storage::io_result::success) \
-      return _result; \
-  }
-
-  storage::io_result tarfs_instance::get_root_node(storage::node_id_t &out) {
-    out = 0;
-    while (true) {
-      char name_buf[255];
-      unsigned name_len;
-      RETURN_MAYBE_NOT_FOUND(read_name(out, name_buf, name_len))
-      if (name_len == 2 && name_buf[0] == '.' && name_buf[1] == '/')
-        return storage::io_result::success;
-      RETURN_MAYBE_NOT_FOUND(next_node(out))
-    }
-  }
-
-  storage::io_result tarfs_instance::get_first_child(storage::node_id_t node,
-    storage::node_id_t &out, storage::directory_iter_t &iter_out
-  ) {
-
-    char name_buf[255];
-    unsigned name_len;
-    RETURN_NOT_SUCCESS(read_name(node, name_buf, name_len))
-
-    out = 0;
-    while (true) {
-
-      char cand_name_buf[255];
-      unsigned cand_name_len;
-      RETURN_MAYBE_NOT_FOUND(read_name(out, cand_name_buf, cand_name_len))
-
-      if (cand_name_len > name_len && utility::starts_with(
-        cand_name_buf, cand_name_len, name_buf, name_len
-      )) {
-        const char *rem = cand_name_buf + name_len;
-        unsigned rem_len = cand_name_len - name_len;
-        unsigned slash = utility::find(rem, rem_len, '/');
-        if (slash == rem_len - 1 || slash == rem_len) {
-          iter_out = out;
-          return storage::io_result::success;
-        }
-      }
-
-      RETURN_MAYBE_NOT_FOUND(next_node(out))
-
-    }
-
-  }
-
-  storage::io_result tarfs_instance::get_next_child(storage::node_id_t node,
-    storage::node_id_t &out, storage::directory_iter_t &iter
-  ) {
-
-    char name_buf[255];
-    unsigned name_len;
-    RETURN_NOT_SUCCESS(read_name(node, name_buf, name_len))
-
-    out = iter;
-
-    RETURN_MAYBE_NOT_FOUND(next_node(out))
-
-    while (true) {
-
-      char cand_name_buf[255];
-      unsigned cand_name_len;
-      RETURN_MAYBE_NOT_FOUND(read_name(out, cand_name_buf, cand_name_len))
-
-      if (cand_name_len > name_len && utility::starts_with(
-        cand_name_buf, cand_name_len, name_buf, name_len
-      )) {
-        const char *rem = cand_name_buf + name_len;
-        unsigned rem_len = cand_name_len - name_len;
-        unsigned slash = utility::find(rem, rem_len, '/');
-        if (slash == rem_len - 1 || slash == rem_len) {
-          iter = out;
-          return storage::io_result::success;
-        }
-      }
-
-      RETURN_MAYBE_NOT_FOUND(next_node(out))
-
-    }
-
-  }
-
-  storage::io_result tarfs_instance::get_child(storage::node_id_t node,
-    storage::node_id_t &out, const char *name, unsigned name_len
-  ) {
-
-    char full_name[255];
-    unsigned full_name_len;
-    RETURN_MAYBE_NOT_FOUND(read_name(node, full_name, full_name_len))
-
-    if (full_name_len + name_len > 255)
-      return storage::io_result::not_supported;
-
-    for (unsigned i = 0; i < name_len; ++i)
-      full_name[full_name_len + i] = name[i];
-    full_name_len += name_len;
-
-    out = 0;
-    while (true) {
-
-      char cand_name[255];
-      unsigned cand_name_len;
-      RETURN_MAYBE_NOT_FOUND(read_name(out, cand_name, cand_name_len))
-
-      if (cand_name_len != full_name_len && cand_name_len != full_name_len + 1)
-        goto next_iter;
-      for (unsigned i = 0; i < full_name_len; ++i)
-        if (cand_name[i] != full_name[i])
-          goto next_iter;
-      if (cand_name_len == full_name_len + 1 &&
-          cand_name[full_name_len] != '/')
-        goto next_iter;
-
-      return storage::io_result::success;
-
-    next_iter:
-      RETURN_MAYBE_NOT_FOUND(next_node(out))
-
-    }
-
-  }
-
-  storage::io_result tarfs_instance::get_name_length(
-    storage::node_id_t node, unsigned &length_out
-  ) {
-
-    char name_buf[255];
-    return get_name(node, name_buf, length_out);
-
-  }
-
-  storage::io_result tarfs_instance::get_name(
-    storage::node_id_t node, char *buffer, unsigned &length_out
-  ) {
-
-    unsigned full_length;
-    char full_buffer[255];
-    RETURN_NOT_SUCCESS(read_name(node, full_buffer, full_length))
-    if (full_length == 2) {
-      //full buffer must be ./
-      length_out = 0;
-      return storage::io_result::success;
-    }
-    if (full_buffer[full_length - 1] == '/')
-      --full_length;
-    unsigned start = utility::find_last(full_buffer, full_length, '/') + 1;
-    length_out = full_length - start;
-    for (unsigned i = 0; i < length_out; ++i)
-      buffer[i] = full_buffer[start + i];
-    return storage::io_result::success;
-
-  }
-
-  storage::io_result tarfs_instance::get_file_length(
-    storage::node_id_t node, uint64_t &length_out
-  ) {
-
-    return read_num(node + 124, 12, length_out);
-
-  }
-
-  storage::io_result tarfs_instance::get_file_type(
-    storage::node_id_t node, storage::file_type &out
-  ) {
-
-    uint64_t ft;
-    storage::io_result result = read_num(node + 156, 1, ft);
-    if (result != storage::io_result::success)
-      return result;
-
-    switch (ft) {
-    case 0:
-      out = storage::file_type::regular_file;
-      return storage::io_result::success;
-    case 2:
-      out = storage::file_type::symlink;
-      return storage::io_result::success;
-    case 5:
-      out = storage::file_type::directory;
-      return storage::io_result::success;
-    default:
-      return storage::io_result::not_supported;
-    }
-
-  }
-
-  storage::io_result tarfs_instance::resize_file(
-    storage::node_id_t, uint64_t
-  ) {
-    //TODO: support resize if sector count isn't changed?
-    return storage::io_result::not_supported;
-  }
-
-  storage::io_result tarfs_instance::read_bytes_from_file(
-    storage::node_id_t node, uint64_t start, uint64_t count, void *into
-  ) {
-    return bd->read_bytes(node + 512 + start, count, into);
-  }
-
-  storage::io_result tarfs_instance::write_bytes_into_file(
-    storage::node_id_t, uint64_t, uint64_t, const void *
-  ) {
-    //TODO: support this.
-    return storage::io_result::not_supported;
-  }
-
-}