/*
* UCW Library -- Fast Buffered I/O
*
- * (c) 1997--2007 Martin Mares <mj@ucw.cz>
+ * (c) 1997--2008 Martin Mares <mj@ucw.cz>
* (c) 2004 Robert Spalek <robert@ucw.cz>
*
* This software may be freely distributed and used according to the terms
#include <string.h>
#include <alloca.h>
-/*
- * Generic buffered I/O. You supply hooks to be called for low-level operations
- * (swapping of buffers, seeking and closing), we do the rest.
+/***
+ * === Internal structure [[internal]]
+ *
+ * Generally speaking, a fastbuf consists of a buffer and a set of callbacks.
+ * All front-end functions operate on the buffer and if the buffer becomes
+ * empty or fills up, they ask the corresponding callback to solve the
+ * situation. Back-ends then differ just in the definition of the callbacks.
+ * The state of the fastbuf is represented by `struct fastbuf`, which
+ * is a simple structure describing the state of the buffer and pointers
+ * to the callback functions.
*
- * Buffer layout when reading:
+ * When we are reading from the fastbuf, the buffer is laid out as follows:
*
* +----------------+---------------------------+
* | read data | free space |
* ^ ^ ^ ^
* buffer bptr bstop bufend
*
- * After the last character is read, bptr == bstop and buffer refill
- * is deferred to the next read attempt. This gives us an easy way
- * how to implement bungetc().
+ * Here `bptr` points to the next character to be read. After the last character is
+ * read, `bptr == bstop` and the `refill` callback gets called upon the next read
+ * attempt to bring further data. This gives us an easy way how to implement @bungetc().
*
- * When writing:
+ * When writing, the situation looks like:
*
* +--------+--------------+--------------------+
* | unused | written data | free space |
* ^ ^ ^ ^
* buffer bstop bptr bufend
*
- * Dirty tricks:
+ * In this case, the `bptr` points at the position where the next character
+ * will be written to. When we want to write, but `bptr == bufend`, we call
+ * the `spout` hook to flush the data and get an empty buffer.
+ *
+ * Several dirty tricks can be played:
*
- * - You can mix reads and writes on the same stream, but you must
- * call bflush() in between and remember that the file position
- * points after the flushed buffer which is not necessarily the same
- * as after the data you've read.
- * - The spout/refill hooks can change not only bptr and bstop, but also
- * the location of the buffer; fb-mem.c takes advantage of it.
- * - In some cases, the user of the bdirect interface can be allowed to modify
+ * - The `spout`/`refill` hooks can change not only `bptr` and `bstop`, but also
+ * the location and size of the buffer; the fb-mem back-end takes advantage of it.
+ * - In some cases, the user of the `bdirect` interface can be allowed to modify
* the data in the buffer to avoid unnecessary copying. If the back-end
- * allows such modifications, it can set can_overwrite_buffer accordingly:
+ * allows such modifications, it can set `fastbuf->can_overwrite_buffer` accordingly:
* * 0 if no modification is allowed,
* * 1 if the user can modify the buffer on the condition that
* the modifications will be undone before calling the next
* fastbuf operation
* * 2 if the user is allowed to overwrite the data in the buffer
- * if bdirect_read_commit_modified() is called afterwards.
+ * if @bdirect_read_commit_modified() is called afterwards.
* In this case, the back-end must be prepared for trimming
* of the buffer which is done by the commit function.
- */
+ *
+ ***/
+/**
+ * This structure contains the state of the fastbuf. See the discussion above
+ * for how it works.
+ **/
struct fastbuf {
- byte is_fastbuf[0]; /* Dummy field for checking of type casts */
- byte *bptr, *bstop; /* Access pointers */
- byte *buffer, *bufend; /* Start and end of the buffer */
- char *name; /* File name for error messages */
- sh_off_t pos; /* Position of bstop in the file */
- int (*refill)(struct fastbuf *); /* Get a buffer with new data */
- void (*spout)(struct fastbuf *); /* Write buffer data to the file */
- int (*seek)(struct fastbuf *, sh_off_t, int); /* Slow path for bseek(), buffer already flushed; returns success */
- void (*close)(struct fastbuf *); /* Close the stream */
+ byte is_fastbuf[0]; /* Dummy field for checking of type casts */
+ byte *bptr, *bstop; /* State of the buffer */
+ byte *buffer, *bufend; /* Start and end of the buffer */
+ char *name; /* File name (used for error messages) */
+ ucw_off_t pos; /* Position of bstop in the file */
+ int (*refill)(struct fastbuf *); /* Get a buffer with new data, returns 0 on EOF */
+ void (*spout)(struct fastbuf *); /* Write buffer data to the file */
+ int (*seek)(struct fastbuf *, ucw_off_t, int);/* Slow path for @bseek(), buffer already flushed; returns success */
+ void (*close)(struct fastbuf *); /* Close the stream */
int (*config)(struct fastbuf *, uns, int); /* Configure the stream */
- int can_overwrite_buffer; /* Can the buffer be altered? (see discussion above) 0=never, 1=temporarily, 2=permanently */
+ int can_overwrite_buffer; /* Can the buffer be altered? 0=never, 1=temporarily, 2=permanently */
};
-/* FastIO on files with several configurable back-ends */
+/***
+ * === Fastbuf on files [[fbparam]]
+ *
+ * If you want to use fastbufs to access files, you can choose one of several
+ * back-ends and set their parameters.
+ ***/
-enum fb_type { /* Which back-end you want to use */
+/**
+ * Back-end types
+ */
+enum fb_type {
FB_STD, /* Standard buffered I/O */
FB_DIRECT, /* Direct I/O bypassing system caches (see fb-direct.c for a description) */
FB_MMAP /* Memory mapped files */
};
+/**
+ * When you open a file fastbuf, you can use this structure to select a back-end
+ * and set its parameters. If you want just an "ordinary" file stream, you can
+ * happily pass NULL instead and the defaults from the configuration file (or
+ * hard-wired defaults if no config file has been read) will be used.
+ */
struct fb_params {
- enum fb_type type;
+ enum fb_type type; /* The chosen back-end */
uns buffer_size; /* 0 for default size */
uns keep_back_buf; /* FB_STD: optimize for bi-directional access */
uns read_ahead; /* FB_DIRECT options */
};
struct cf_section;
-extern struct cf_section fbpar_cf;
-extern struct fb_params fbpar_def;
+extern struct cf_section fbpar_cf; /** Configuration section with which you can fill the `fb_params` **/
+extern struct fb_params fbpar_def; /** The default `fb_params` **/
-struct fastbuf *bopen_file(const char *name, int mode, struct fb_params *params); /* Use params==NULL for defaults */
-struct fastbuf *bopen_file_try(const char *name, int mode, struct fb_params *params);
+/**
+ * Opens a file with file mode @mode (see the man page of open()).
+ * Use @params to select the fastbuf back-end and its parameters or
+ * pass NULL if you are fine with defaults.
+ *
+ * Dies if the file does not exist.
+ **/
+struct fastbuf *bopen_file(const char *name, int mode, struct fb_params *params);
+struct fastbuf *bopen_file_try(const char *name, int mode, struct fb_params *params); /** Like bopen_file(), but returns NULL on failure. **/
+
+/**
+ * Opens a temporary file.
+ * It is placed with other temp files and it is deleted when closed.
+ * Again, use NULL for @params if you want the defaults.
+ **/
struct fastbuf *bopen_tmp_file(struct fb_params *params);
-struct fastbuf *bopen_fd(int fd, struct fb_params *params);
-/* FastIO on standard files (shortcuts for FB_STD) */
+/**
+ * Creates a fastbuf from a file descriptor @fd and sets its filename
+ * to @name (the name is used only in error messages).
+ * When the fastbuf is closed, the fd is closed as well. You can override
+ * this behavior by calling @bconfig().
+ */
+struct fastbuf *bopen_fd_name(int fd, struct fb_params *params, const char *name);
+static inline struct fastbuf *bopen_fd(int fd, struct fb_params *params) /** Same as above, but with an auto-generated filename. **/
+{
+ return bopen_fd_name(fd, params, NULL);
+}
-struct fastbuf *bopen(const char *name, uns mode, uns buflen);
-struct fastbuf *bopen_try(const char *name, uns mode, uns buflen);
-struct fastbuf *bopen_tmp(uns buflen);
-struct fastbuf *bfdopen(int fd, uns buflen);
-struct fastbuf *bfdopen_shared(int fd, uns buflen);
+/**
+ * Flushes all buffers and makes sure that they are written to the disk.
+ **/
void bfilesync(struct fastbuf *b);
-/* Temporary files */
+/***
+ * === Fastbufs on regular files [[fbfile]]
+ *
+ * If you want to use the `FB_STD` back-end and not worry about setting
+ * up any parameters, there is a couple of shortcuts.
+ ***/
+
+struct fastbuf *bopen(const char *name, uns mode, uns buflen); /** Equivalent to @bopen_file() with `FB_STD` back-end. **/
+struct fastbuf *bopen_try(const char *name, uns mode, uns buflen); /** Equivalent to @bopen_file_try() with `FB_STD` back-end. **/
+struct fastbuf *bopen_tmp(uns buflen); /** Equivalent to @bopen_tmp_file() with `FB_STD` back-end. **/
+struct fastbuf *bfdopen(int fd, uns buflen); /** Equivalent to @bopen_fd() with `FB_STD` back-end. **/
+struct fastbuf *bfdopen_shared(int fd, uns buflen); /** Like @bfdopen(), but it does not close the @fd on @bclose(). **/
+
+/***
+ * === Temporary files [[fbtemp]]
+ *
+ * Usually, @bopen_tmp_file() is the best way how to come to a temporary file.
+ * However, in some specific cases you can need more, so there is also a set
+ * of more general functions.
+ ***/
#define TEMP_FILE_NAME_LEN 256
-void temp_file_name(char *name);
+
+/**
+ * Generates a temporary filename and stores it to the @name_buf (of size
+ * at least * `TEMP_FILE_NAME_LEN`). If @open_flags are not NULL, flags that
+ * should be OR-ed with other flags to open() will be stored there.
+ *
+ * The location and style of temporary files is controlled by the configuration.
+ * By default, the system temp directory (`$TMPDIR` or `/tmp`) is used.
+ *
+ * If the location is a publicly writeable directory (like `/tmp`), the
+ * generated filename cannot be guaranteed to be unique, so @open_flags
+ * will include `O_EXCL` and you have to check the result of open() and
+ * iterate if needed.
+ *
+ * This function is not specific to fastbufs, it can be used separately.
+ **/
+void temp_file_name(char *name_buf, int *open_flags);
+
+/**
+ * Opens a temporary file and returns its file descriptor.
+ * You specify the file @mode and @open_flags passed to open().
+ *
+ * If the @name_buf (of at last `TEMP_FILE_NAME_LEN` chars) is not NULL,
+ * the filename is also stored in it.
+ *
+ * This function is not specific to fastbufs, it can be used separately.
+ */
+int open_tmp(char *name_buf, int open_flags, int mode);
+
+/**
+ * Sometimes, a file is created as temporary and then moved to a stable
+ * location. This function takes a fastbuf created by @bopen_tmp_file()
+ * or @bopen_tmp(), marks it as permanent, closes it and renames it to
+ * @name.
+ *
+ * Please note that it assumes that the temporary file and the @name
+ * are on the same volume (otherwise, rename() fails), so you might
+ * want to configure a special location for the temporary files
+ * beforehand.
+ */
void bfix_tmp_file(struct fastbuf *fb, const char *name);
/* Internal functions of some file back-ends */
void bclose_file_helper(struct fastbuf *f, int fd, int is_temp_file);
-/* FastIO on in-memory streams */
-
-struct fastbuf *fbmem_create(uns blocksize); /* Create stream and return its writing fastbuf */
-struct fastbuf *fbmem_clone_read(struct fastbuf *); /* Create reading fastbuf */
+/***
+ * === Fastbufs on file fragments [[fblim]]
+ *
+ * The `fblim` back-end reads from a file handle, but at most a given
+ * number of bytes. This is frequently used for reading from sockets.
+ ***/
-/* FastI on file descriptors with limit */
+struct fastbuf *bopen_limited_fd(int fd, uns bufsize, uns limit); /** Create a fastbuf which reads at most @limit bytes from @fd. **/
-struct fastbuf *bopen_limited_fd(int fd, uns bufsize, uns limit);
+/***
+ * === Fastbufs on in-memory streams [[fbmem]]
+ *
+ * The `fbmem` back-end keeps the whole contents of the stream
+ * in memory (as a linked list of memory blocks, so address space
+ * fragmentation is avoided).
+ *
+ * First, you use @fbmem_create() to create the stream and the fastbuf
+ * used for writing to it. Then you can call @fbmem_clone_read() to get
+ * an arbitrary number of fastbuf for reading from the stream.
+ ***/
-/* FastIO on static buffers */
+struct fastbuf *fbmem_create(uns blocksize); /** Create stream and return its writing fastbuf. **/
+struct fastbuf *fbmem_clone_read(struct fastbuf *f); /** Given a writing fastbuf, create a new reading fastbuf. **/
+/***
+ * === Fastbufs on static buffers [[fbbuf]]
+ *
+ * The `fbbuf` back-end stores the stream in a given block of memory.
+ * This is useful for parsing and generating of complex data structures.
+ ***/
+
+/**
+ * Creates a read-only fastbuf that takes its data from a given buffer.
+ * The fastbuf structure is allocated by the caller and pointed to by @f.
+ * The @buffer and @size specify the location and size of the buffer.
+ *
+ * In some cases, the front-ends can take advantage of rewriting the contents
+ * of the buffer temporarily. In this case, set @can_overwrite as described
+ * in <<internal,Internals>>. If you do not care, keep @can_overwrite zero.
+ *
+ * It is not possible to close this fastbuf.
+ */
void fbbuf_init_read(struct fastbuf *f, byte *buffer, uns size, uns can_overwrite);
+
+/**
+ * Creates a write-only fastbuf which writes into a provided memory buffer.
+ * The fastbuf structure is allocated by the caller and pointed to by @f.
+ * An attempt to write behind the end of the buffer dies.
+ *
+ * Data are written directly into the buffer, so it is not necessary to call @bflush()
+ * at any moment.
+ *
+ * It is not possible to close this fastbuf.
+ */
void fbbuf_init_write(struct fastbuf *f, byte *buffer, uns size);
-static inline uns
-fbbuf_count_written(struct fastbuf *f)
+
+static inline uns fbbuf_count_written(struct fastbuf *f) /** Calculates, how many bytes were already written into the buffer. **/
{
return f->bptr - f->bstop;
}
-/* FastIO on recyclable growing buffers */
+/***
+ * === Fastbuf on recyclable growing buffers [[fbgrow]]
+ *
+ * The `fbgrow` back-end keeps the stream in a contiguous buffer stored in the
+ * main memory, but unlike <<fbmem,`fbmem`>>, the buffer does not have a fixed
+ * size and it is expanded to accomodate all data.
+ *
+ * At every moment, you can use `fastbuf->buffer` to gain access to the stream.
+ ***/
-struct fastbuf *fbgrow_create(unsigned basic_size);
-void fbgrow_reset(struct fastbuf *b); /* Reset stream and prepare for writing */
-void fbgrow_rewind(struct fastbuf *b); /* Prepare for reading */
+struct fastbuf *fbgrow_create(unsigned basic_size); /** Create the growing buffer pre-allocated to @basic_size bytes. **/
+void fbgrow_reset(struct fastbuf *b); /** Reset stream and prepare for writing. **/
+void fbgrow_rewind(struct fastbuf *b); /** Prepare for reading (of already written data). **/
-/* FastO on memory pools */
+/***
+ * === Fastbuf on memory pools [[fbpool]]
+ *
+ * The write-only `fbpool` back-end also keeps the stream in a contiguous
+ * buffer, but this time the buffer is allocated from within a memory pool.
+ ***/
struct mempool;
-struct fbpool {
+struct fbpool { /** Structure for fastbufs & mempools. **/
struct fastbuf fb;
struct mempool *mp;
};
-void fbpool_init(struct fbpool *fb); /* Initialize a new fastbuf */
+/**
+ * Initialize a new `fbpool`. The structure is allocated by the caller.
+ **/
+void fbpool_init(struct fbpool *fb); /** Initialize a new mempool fastbuf. **/
+/**
+ * Start a new continuous block and prepare for writing (see <<mempool:mp_start()>>).
+ * Provide the memory pool you want to use for this block as @mp.
+ **/
void fbpool_start(struct fbpool *fb, struct mempool *mp, uns init_size);
- /* Start a new continuous block and prepare for writing (see mp_start()) */
-void *fbpool_end(struct fbpool *fb); /* Close the block and return its address (see mp_end()).
- The length can be determined with mp_size(mp, ptr). */
-
-/* FastO with atomic writes for multi-threaded programs */
+/**
+ * Close the block and return the address of its start (see <<mempool:mp_end()>>).
+ * The length can be determined by calling <<mempool:mp_size(mp, ptr)>>.
+ **/
+void *fbpool_end(struct fbpool *fb);
+
+/***
+ * === Atomic files for multi-threaded programs [[fbatomic]]
+ *
+ * This fastbuf backend is designed for cases when several threads
+ * of a single program append records to a common file and while the
+ * record can mix in an arbitrary way, the bytes inside a single
+ * record must remain uninterrupted.
+ *
+ * In case of files with fixed record size, we just allocate the
+ * buffer to hold a whole number of records and take advantage
+ * of the atomicity of the write() system call.
+ *
+ * With variable-sized records, we need another solution: when
+ * writing a record, we keep the fastbuf in a locked state, which
+ * prevents buffer flushing (and if the buffer becomes full, we extend it),
+ * and we wait for an explicit commit operation which write()s the buffer
+ * if the free space in the buffer falls below the expected maximum record
+ * length.
+ *
+ * Please note that initialization of the clones is not thread-safe,
+ * so you have to serialize it yourself.
+ ***/
struct fb_atomic {
struct fastbuf fb;
};
#define FB_ATOMIC(f) ((struct fb_atomic *)(f)->is_fastbuf)
+/**
+ * Open an atomic fastbuf.
+ * If @master is NULL, the file @name is opened. If it is non-null,
+ * a new clone of an existing atomic fastbuf is created.
+ *
+ * If the file has fixed record length, just set @record_len to it.
+ * Otherwise set @record_len to the expected maximum record length
+ * with a negative sign (you need not fit in this length, but as long
+ * as you do, the fastbuf is more efficient) and call @fbatomic_commit()
+ * after each record.
+ *
+ * You can specify @record_len, if it is known (for optimisations).
+ *
+ * The file is closed when all fastbufs using it are closed.
+ **/
struct fastbuf *fbatomic_open(const char *name, struct fastbuf *master, uns bufsize, int record_len);
void fbatomic_internal_write(struct fastbuf *b);
-static inline void
-fbatomic_commit(struct fastbuf *b)
+/**
+ * Declare that you have finished writing a record. This is required only
+ * if a fixed record size was not specified.
+ **/
+static inline void fbatomic_commit(struct fastbuf *b)
{
if (b->bptr >= ((struct fb_atomic *)b)->expected_max_bptr)
fbatomic_internal_write(b);
}
-/* Configuring stream parameters */
+/*** === Configuring stream parameters [[bconfig]] ***/
-enum bconfig_type {
+enum bconfig_type { /** Parameters that could be configured. **/
BCONFIG_IS_TEMP_FILE, /* 0=normal file, 1=temporary file, 2=shared fd */
BCONFIG_KEEP_BACK_BUF, /* Optimize for bi-directional access */
};
-int bconfig(struct fastbuf *f, uns type, int data);
+int bconfig(struct fastbuf *f, uns type, int data); /** Configure a fastbuf. Returns previous value. **/
-/* Universal functions working on all fastbuf's */
+/*** === Universal functions working on all fastbuf's [[ffbasic]] ***/
+/**
+ * Close and free fastbuf.
+ * Can not be used for fastbufs not returned from function (initialized in a parameter, for example the one from `fbbuf_init_read`).
+ */
void bclose(struct fastbuf *f);
-void bflush(struct fastbuf *f);
-void bseek(struct fastbuf *f, sh_off_t pos, int whence);
-void bsetpos(struct fastbuf *f, sh_off_t pos);
-void brewind(struct fastbuf *f);
-sh_off_t bfilesize(struct fastbuf *f); /* -1 if not seekable */
+void bflush(struct fastbuf *f); /** Write data (if it makes any sense, do not use for in-memory buffers). **/
+void bseek(struct fastbuf *f, ucw_off_t pos, int whence); /** Seek in the buffer. See `man fseek` for description of @whence. Only for seekable fastbufs. **/
+void bsetpos(struct fastbuf *f, ucw_off_t pos); /** Set position to @pos bytes from beginning. Only for seekable fastbufs. **/
+void brewind(struct fastbuf *f); /** Go to the beginning of the fastbuf. Only for seekable ones. **/
+ucw_off_t bfilesize(struct fastbuf *f); /** How large is the file? -1 if not seekable. **/
-static inline sh_off_t btell(struct fastbuf *f)
+static inline ucw_off_t btell(struct fastbuf *f) /** Where am I (from the beginning)? **/
{
return f->pos + (f->bptr - f->bstop);
}
int bgetc_slow(struct fastbuf *f);
-static inline int bgetc(struct fastbuf *f)
+static inline int bgetc(struct fastbuf *f) /** Return next character from the buffer. **/
{
return (f->bptr < f->bstop) ? (int) *f->bptr++ : bgetc_slow(f);
}
int bpeekc_slow(struct fastbuf *f);
-static inline int bpeekc(struct fastbuf *f)
+static inline int bpeekc(struct fastbuf *f) /** Return next character from the buffer, but keep the current position. **/
{
return (f->bptr < f->bstop) ? (int) *f->bptr : bpeekc_slow(f);
}
-static inline void bungetc(struct fastbuf *f)
+static inline void bungetc(struct fastbuf *f) /** Return last read character back. Only one back is guaranteed to work. **/
{
f->bptr--;
}
void bputc_slow(struct fastbuf *f, uns c);
-static inline void bputc(struct fastbuf *f, uns c)
+static inline void bputc(struct fastbuf *f, uns c) /** Write a single character. **/
{
if (f->bptr < f->bufend)
*f->bptr++ = c;
bputc_slow(f, c);
}
-static inline uns
-bavailr(struct fastbuf *f)
+static inline uns bavailr(struct fastbuf *f)
{
return f->bstop - f->bptr;
}
-static inline uns
-bavailw(struct fastbuf *f)
+static inline uns bavailw(struct fastbuf *f)
{
return f->bufend - f->bptr;
}
uns bread_slow(struct fastbuf *f, void *b, uns l, uns check);
+/**
+ * Read at most @l bytes of data into @b.
+ * Returns number of bytes read.
+ * 0 means end of file.
+ */
static inline uns bread(struct fastbuf *f, void *b, uns l)
{
if (bavailr(f) >= l)
return bread_slow(f, b, l, 0);
}
+/**
+ * Reads exactly @l bytes of data into @b.
+ * If at the end of file, it returns 0.
+ * If there are data, but less than @l, it dies.
+ */
static inline uns breadb(struct fastbuf *f, void *b, uns l)
{
if (bavailr(f) >= l)
}
void bwrite_slow(struct fastbuf *f, const void *b, uns l);
-static inline void bwrite(struct fastbuf *f, const void *b, uns l)
+static inline void bwrite(struct fastbuf *f, const void *b, uns l) /** Writes buffer @b of length @l into fastbuf. **/
{
if (bavailw(f) >= l)
{
bwrite_slow(f, b, l);
}
-/*
- * Functions for reading of strings:
- *
- * bgets() reads a line, strip the trailing '\n' and return a pointer
- * to the terminating 0 or NULL on EOF. Dies if the line is too long.
- * bgets0() does the same for 0-terminated strings.
- * bgets_nodie() a variant of bgets() which returns either the length of the
- * string (excluding the terminator) or -1 if the line does not fit
- * in the buffer. In such cases, it returns after reading exactly `l'
- * bytes of input.
- * bgets_bb() a variant of bgets() which allocates the string in a growing buffer
- * bgets_mp() the same, but in a mempool
- * bgets_stk() the same, but on the stack by alloca()
- */
-
+/**
+ * Reads a line into @b and strips trailing `\n`.
+ * Returns pointer to the terminating 0 or NULL on `EOF`.
+ * Dies if the line is longer than @l.
+ **/
char *bgets(struct fastbuf *f, char *b, uns l);
-char *bgets0(struct fastbuf *f, char *b, uns l);
+char *bgets0(struct fastbuf *f, char *b, uns l); /** The same as @bgets(), but for 0-terminated strings. **/
+/**
+ * Returns either length of read string (excluding the terminator) or -1 if it is too long.
+ * In such cases exactly @l bytes are read.
+ */
int bgets_nodie(struct fastbuf *f, char *b, uns l);
struct mempool;
struct bb_t;
+/**
+ * Read a string, strip the trailing `\n` and store it into growing buffer @b.
+ * Dies if the line is longer than @limit.
+ **/
uns bgets_bb(struct fastbuf *f, struct bb_t *b, uns limit);
+/**
+ * Read a string, strip the trailing `\n` and store it into buffer allocated from a memory pool.
+ **/
char *bgets_mp(struct fastbuf *f, struct mempool *mp);
struct bgets_stk_struct {
};
void bgets_stk_init(struct bgets_stk_struct *s);
void bgets_stk_step(struct bgets_stk_struct *s);
-#define bgets_stk(fb) ({ struct bgets_stk_struct _s; _s.f = (fb); for (bgets_stk_init(&_s); _s.cur_len; _s.cur_buf = alloca(_s.cur_len), bgets_stk_step(&_s)); _s.cur_buf; })
-static inline void
-bputs(struct fastbuf *f, const char *b)
+/**
+ * Read a string, strip the trailing `\n` and store it on the stack (allocated using alloca()).
+ **/
+#define bgets_stk(fb) \
+ ({ struct bgets_stk_struct _s; _s.f = (fb); for (bgets_stk_init(&_s); _s.cur_len; _s.cur_buf = alloca(_s.cur_len), bgets_stk_step(&_s)); _s.cur_buf; })
+
+/**
+ * Write a string, without 0 or `\n` at the end.
+ **/
+static inline void bputs(struct fastbuf *f, const char *b)
{
bwrite(f, b, strlen(b));
}
-static inline void
-bputs0(struct fastbuf *f, const char *b)
+/**
+ * Write string, including terminating 0.
+ **/
+static inline void bputs0(struct fastbuf *f, const char *b)
{
bwrite(f, b, strlen(b)+1);
}
-static inline void
-bputsn(struct fastbuf *f, const char *b)
+/**
+ * Write string and append a newline to the end.
+ **/
+static inline void bputsn(struct fastbuf *f, const char *b)
{
bputs(f, b);
bputc(f, '\n');
}
void bbcopy_slow(struct fastbuf *f, struct fastbuf *t, uns l);
-static inline void
-bbcopy(struct fastbuf *f, struct fastbuf *t, uns l)
+/**
+ * Copy @l bytes of data from fastbuf @f to fastbuf @t.
+ **/
+static inline void bbcopy(struct fastbuf *f, struct fastbuf *t, uns l)
{
if (bavailr(f) >= l && bavailw(t) >= l)
{
}
int bskip_slow(struct fastbuf *f, uns len);
-static inline int bskip(struct fastbuf *f, uns len)
+static inline int bskip(struct fastbuf *f, uns len) /** Skip @len bytes without reading them. **/
{
if (bavailr(f) >= len)
{
return bskip_slow(f, len);
}
-/* Direct I/O on buffers */
+/*** === Direct I/O on buffers ***/
+// TODO Documentation -- what do they do?
static inline uns
bdirect_read_prepare(struct fastbuf *f, byte **buf)
f->bptr = pos;
}
-/* Formatted output */
+/*** === Formatted output ***/
-int bprintf(struct fastbuf *b, const char *msg, ...) FORMAT_CHECK(printf,2,3);
-int vbprintf(struct fastbuf *b, const char *msg, va_list args);
+/**
+ * printf into a fastbuf.
+ **/
+int bprintf(struct fastbuf *b, const char *msg, ...)
+ FORMAT_CHECK(printf,2,3);
+int vbprintf(struct fastbuf *b, const char *msg, va_list args); /** vprintf into a fastbuf. **/
#endif
projects / libucw.git / blobdiff