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Diffstat (limited to 'src/nvim/file.c')
| -rw-r--r-- | src/nvim/file.c | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/src/nvim/file.c b/src/nvim/file.c new file mode 100644 index 0000000000..bc230ecf00 --- /dev/null +++ b/src/nvim/file.c @@ -0,0 +1,164 @@ +/// @file file.c +/// +/// Buffered reading/writing to a file. Unlike fileio.c this is not dealing with +/// Neovim stuctures for buffer, with autocommands, etc: just fopen/fread/fwrite +/// replacement. + +#include <unistd.h> +#include <stddef.h> +#include <stdbool.h> + +#include <uv.h> + +#include "nvim/file.h" +#include "nvim/memory.h" +#include "nvim/os/os.h" +#include "nvim/globals.h" + +#ifdef INCLUDE_GENERATED_DECLARATIONS +# include "file.c.generated.h" +#endif + +/// Open file +/// +/// @param[out] ret_fp Address where information needed for reading from or +/// writing to a file is saved +/// @param[in] fname File name to open. +/// @param[in] flags Flags, @see FileOpenFlags. +/// @param[in] mode Permissions for the newly created file (ignored if flags +/// does not have FILE_CREATE\*). +/// +/// @return Error code (@see os_strerror()) or 0. +int file_open(FileDescriptor *const ret_fp, const char *const fname, + const int flags, const int mode) + FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT +{ + int fd; + + fd = os_open(fname, flags, mode); + + if (fd < 0) { + return fd; + } + + ret_fp->fd = fd; + ret_fp->eof = false; + return 0; +} + +/// Like file_open(), but allocate and return ret_fp +/// +/// @param[out] error Error code, @see os_strerror(). Is set to zero on +/// success. +/// @param[in] fname File name to open. +/// @param[in] flags Flags, @see FileOpenFlags. +/// @param[in] mode Permissions for the newly created file (ignored if flags +/// does not have FILE_CREATE\*). +/// +/// @return [allocated] Opened file or NULL in case of error. +FileDescriptor *file_open_new(int *const error, const char *const fname, + const int flags, const int mode) + FUNC_ATTR_NONNULL_ALL FUNC_ATTR_MALLOC FUNC_ATTR_WARN_UNUSED_RESULT +{ + FileDescriptor *const fp = xmalloc(sizeof(*fp)); + if ((*error = file_open(fp, fname, flags, mode)) != 0) { + xfree(fp); + return NULL; + } + return fp; +} + +/// Close file +/// +/// @param[in,out] fp File to close. +/// +/// @return 0 or error code. +int file_close(FileDescriptor *const fp) FUNC_ATTR_NONNULL_ALL +{ + const int error = file_fsync(fp); + const int error2 = os_close(fp->fd); + if (error2 != 0) { + return error2; + } + return error; +} + +/// Close and free file obtained using file_open_new() +/// +/// @param[in,out] fp File to close. +/// +/// @return 0 or error code. +int file_free(FileDescriptor *const fp) FUNC_ATTR_NONNULL_ALL +{ + const int ret = file_close(fp); + xfree(fp); + return ret; +} + +/// Flush file modifications to disk +/// +/// @param[in,out] fp File to work with. +/// +/// @return 0 or error code. +int file_fsync(FileDescriptor *const fp) + FUNC_ATTR_NONNULL_ALL +{ + return os_fsync(fp->fd); +} + +/// Read from file +/// +/// @param[in,out] fp File to work with. +/// @param[out] ret_buf Buffer to read to. Must not be NULL. +/// @param[in] size Number of bytes to read. Buffer must have at least ret_buf +/// bytes. +/// +/// @return error_code (< 0) or number of bytes read. +ptrdiff_t file_read(FileDescriptor *const fp, char *const ret_buf, + const size_t size) + FUNC_ATTR_NONNULL_ALL FUNC_ATTR_WARN_UNUSED_RESULT +{ + return os_read(fp->fd, &fp->eof, ret_buf, size); +} + +/// Write to a file +/// +/// @param[in] fd File descriptor to write to. +/// @param[in] buf Data to write. May be NULL if size is zero. +/// @param[in] size Amount of bytes to write. +/// +/// @return Number of bytes written or libuv error code (< 0). +ptrdiff_t file_write(FileDescriptor *const fp, const char *const buf, + const size_t size) + FUNC_ATTR_WARN_UNUSED_RESULT FUNC_ATTR_NONNULL_ARG(1) +{ + return os_write(fp->fd, buf, size); +} + +/// Buffer used for skipping. Its contents is undefined and should never be +/// used. +static char skipbuf[IOSIZE]; + +/// Skip some bytes +/// +/// This is like `fseek(fp, size, SEEK_CUR)`, but actual implementation simply +/// reads to a buffer and discards the result. +ptrdiff_t file_skip(FileDescriptor *const fp, const size_t size) + FUNC_ATTR_NONNULL_ALL +{ + size_t read_bytes = 0; + do { + ptrdiff_t new_read_bytes = file_read( + fp, skipbuf, (size_t)(size - read_bytes > sizeof(skipbuf) + ? sizeof(skipbuf) + : size - read_bytes)); + if (new_read_bytes < 0) { + return new_read_bytes; + } else if (new_read_bytes == 0) { + break; + } + read_bytes += (size_t)new_read_bytes; + } while (read_bytes < size && !fp->eof); + + return (ptrdiff_t)read_bytes; +} |