diff options
Diffstat (limited to 'deps/uv/src/win/fs-fd-hash-inl.h')
| -rw-r--r-- | deps/uv/src/win/fs-fd-hash-inl.h | 178 |
1 files changed, 178 insertions, 0 deletions
diff --git a/deps/uv/src/win/fs-fd-hash-inl.h b/deps/uv/src/win/fs-fd-hash-inl.h new file mode 100644 index 0000000000..7a203d232d --- /dev/null +++ b/deps/uv/src/win/fs-fd-hash-inl.h @@ -0,0 +1,178 @@ +#ifndef UV_WIN_FS_FD_HASH_INL_H_ +#define UV_WIN_FS_FD_HASH_INL_H_ + +#include "uv.h" +#include "internal.h" + +/* Files are only inserted in uv__fd_hash when the UV_FS_O_FILEMAP flag is + * specified. Thus, when uv__fd_hash_get returns true, the file mapping in the + * info structure should be used for read/write operations. + * + * If the file is empty, the mapping field will be set to + * INVALID_HANDLE_VALUE. This is not an issue since the file mapping needs to + * be created anyway when the file size changes. + * + * Since file descriptors are sequential integers, the modulo operator is used + * as hashing function. For each bucket, a single linked list of arrays is + * kept to minimize allocations. A statically allocated memory buffer is kept + * for the first array in each bucket. */ + + +#define UV__FD_HASH_SIZE 256 +#define UV__FD_HASH_GROUP_SIZE 16 + +struct uv__fd_info_s { + int flags; + BOOLEAN is_directory; + HANDLE mapping; + LARGE_INTEGER size; + LARGE_INTEGER current_pos; +}; + +struct uv__fd_hash_entry_s { + uv_file fd; + struct uv__fd_info_s info; +}; + +struct uv__fd_hash_entry_group_s { + struct uv__fd_hash_entry_s entries[UV__FD_HASH_GROUP_SIZE]; + struct uv__fd_hash_entry_group_s* next; +}; + +struct uv__fd_hash_bucket_s { + size_t size; + struct uv__fd_hash_entry_group_s* data; +}; + + +static uv_mutex_t uv__fd_hash_mutex; + +static struct uv__fd_hash_entry_group_s + uv__fd_hash_entry_initial[UV__FD_HASH_SIZE * UV__FD_HASH_GROUP_SIZE]; +static struct uv__fd_hash_bucket_s uv__fd_hash[UV__FD_HASH_SIZE]; + + +INLINE static void uv__fd_hash_init(void) { + int i, err; + + err = uv_mutex_init(&uv__fd_hash_mutex); + if (err) { + uv_fatal_error(err, "uv_mutex_init"); + } + + for (i = 0; i < ARRAY_SIZE(uv__fd_hash); ++i) { + uv__fd_hash[i].size = 0; + uv__fd_hash[i].data = + uv__fd_hash_entry_initial + i * UV__FD_HASH_GROUP_SIZE; + } +} + +#define FIND_COMMON_VARIABLES \ + unsigned i; \ + unsigned bucket = fd % ARRAY_SIZE(uv__fd_hash); \ + struct uv__fd_hash_entry_s* entry_ptr = NULL; \ + struct uv__fd_hash_entry_group_s* group_ptr; \ + struct uv__fd_hash_bucket_s* bucket_ptr = &uv__fd_hash[bucket]; + +#define FIND_IN_GROUP_PTR(group_size) \ + do { \ + for (i = 0; i < group_size; ++i) { \ + if (group_ptr->entries[i].fd == fd) { \ + entry_ptr = &group_ptr->entries[i]; \ + break; \ + } \ + } \ + } while (0) + +#define FIND_IN_BUCKET_PTR() \ + do { \ + size_t first_group_size = bucket_ptr->size % UV__FD_HASH_GROUP_SIZE; \ + if (bucket_ptr->size != 0 && first_group_size == 0) \ + first_group_size = UV__FD_HASH_GROUP_SIZE; \ + group_ptr = bucket_ptr->data; \ + FIND_IN_GROUP_PTR(first_group_size); \ + for (group_ptr = group_ptr->next; \ + group_ptr != NULL && entry_ptr == NULL; \ + group_ptr = group_ptr->next) \ + FIND_IN_GROUP_PTR(UV__FD_HASH_GROUP_SIZE); \ + } while (0) + +INLINE static int uv__fd_hash_get(int fd, struct uv__fd_info_s* info) { + FIND_COMMON_VARIABLES + + uv_mutex_lock(&uv__fd_hash_mutex); + + FIND_IN_BUCKET_PTR(); + + if (entry_ptr != NULL) { + *info = entry_ptr->info; + } + + uv_mutex_unlock(&uv__fd_hash_mutex); + return entry_ptr != NULL; +} + +INLINE static void uv__fd_hash_add(int fd, struct uv__fd_info_s* info) { + FIND_COMMON_VARIABLES + + uv_mutex_lock(&uv__fd_hash_mutex); + + FIND_IN_BUCKET_PTR(); + + if (entry_ptr == NULL) { + i = bucket_ptr->size % UV__FD_HASH_GROUP_SIZE; + + if (bucket_ptr->size != 0 && i == 0) { + struct uv__fd_hash_entry_group_s* new_group_ptr = + uv__malloc(sizeof(*new_group_ptr)); + if (new_group_ptr == NULL) { + uv_fatal_error(ERROR_OUTOFMEMORY, "uv__malloc"); + } + new_group_ptr->next = bucket_ptr->data; + bucket_ptr->data = new_group_ptr; + } + + bucket_ptr->size += 1; + entry_ptr = &bucket_ptr->data->entries[i]; + entry_ptr->fd = fd; + } + + entry_ptr->info = *info; + + uv_mutex_unlock(&uv__fd_hash_mutex); +} + +INLINE static int uv__fd_hash_remove(int fd, struct uv__fd_info_s* info) { + FIND_COMMON_VARIABLES + + uv_mutex_lock(&uv__fd_hash_mutex); + + FIND_IN_BUCKET_PTR(); + + if (entry_ptr != NULL) { + *info = entry_ptr->info; + + bucket_ptr->size -= 1; + + i = bucket_ptr->size % UV__FD_HASH_GROUP_SIZE; + if (entry_ptr != &bucket_ptr->data->entries[i]) { + *entry_ptr = bucket_ptr->data->entries[i]; + } + + if (bucket_ptr->size != 0 && + bucket_ptr->size % UV__FD_HASH_GROUP_SIZE == 0) { + struct uv__fd_hash_entry_group_s* old_group_ptr = bucket_ptr->data; + bucket_ptr->data = old_group_ptr->next; + uv__free(old_group_ptr); + } + } + + uv_mutex_unlock(&uv__fd_hash_mutex); + return entry_ptr != NULL; +} + +#undef FIND_COMMON_VARIABLES +#undef FIND_IN_GROUP_PTR +#undef FIND_IN_BUCKET_PTR + +#endif /* UV_WIN_FS_FD_HASH_INL_H_ */ |