src/chunk.h

   1 #ifndef _CHUNK_H_
   2 #define _CHUNK_H_
   3 #include "first.h"
   4
   5 #include "buffer.h"
   6 #include "array.h"
   7
   8 typedef struct chunk {
   9         enum { MEM_CHUNK, FILE_CHUNK } type;
  10
  11         buffer *mem; /* either the storage of the mem-chunk or the read-ahead buffer */
  12
  13         struct {
  14                 /* filechunk */
  15                 buffer *name; /* name of the file */
  16                 off_t  start; /* starting offset in the file */
  17                 off_t  length; /* octets to send from the starting offset */
  18
  19                 int    fd;
  20                 struct {
  21                         char   *start; /* the start pointer of the mmap'ed area */
  22                         size_t length; /* size of the mmap'ed area */
  23                         off_t  offset; /* start is <n> octet away from the start of the file */
  24                 } mmap;
  25
  26                 int is_temp; /* file is temporary and will be deleted if on cleanup */
  27         } file;
  28
  29         /* the size of the chunk is either:
  30          * - mem-chunk: buffer_string_length(chunk::mem)
  31          * - file-chunk: chunk::file.length
  32          */
  33         off_t  offset; /* octets sent from this chunk */
  34
  35         struct chunk *next;
  36 } chunk;
  37
  38 typedef struct {
  39         chunk *first;
  40         chunk *last;
  41
  42         chunk *unused;
  43         size_t unused_chunks;
  44
  45         off_t bytes_in, bytes_out;
  46
  47         array *tempdirs;
  48         unsigned int upload_temp_file_size;
  49         unsigned int tempdir_idx;
  50 } chunkqueue;
  51
  52 chunkqueue *chunkqueue_init(void);
  53 void chunkqueue_set_tempdirs(chunkqueue *cq, array *tempdirs, unsigned int upload_temp_file_size);
  54 void chunkqueue_append_file(chunkqueue *cq, buffer *fn, off_t offset, off_t len); /* copies "fn" */
  55 void chunkqueue_append_file_fd(chunkqueue *cq, buffer *fn, int fd, off_t offset, off_t len); /* copies "fn" */
  56 void chunkqueue_append_mem(chunkqueue *cq, const char *mem, size_t len); /* copies memory */
  57 void chunkqueue_append_buffer(chunkqueue *cq, buffer *mem); /* may reset "mem" */
  58 void chunkqueue_prepend_buffer(chunkqueue *cq, buffer *mem); /* may reset "mem" */
  59
  60 /* functions to handle buffers to read into: */
  61 /* return a pointer to a buffer in *mem with size *len;
  62  *  it should be at least min_size big, and use alloc_size if
  63  *  new memory is allocated.
  64  * modifying the chunkqueue invalidates the memory area.
  65  * should always be followed by chunkqueue_get_memory(),
  66  *  even if nothing was read.
  67  * pass 0 for min_size/alloc_size for default values
  68  */
  69 void chunkqueue_get_memory(chunkqueue *cq, char **mem, size_t *len, size_t min_size, size_t alloc_size);
  70 /* append first len bytes of the memory queried with
  71  * chunkqueue_get_memory to the chunkqueue
  72  */
  73 void chunkqueue_use_memory(chunkqueue *cq, size_t len);
  74
  75 /* mark first "len" bytes as written (incrementing chunk offsets)
  76  * and remove finished chunks
  77  */
  78 void chunkqueue_mark_written(chunkqueue *cq, off_t len);
  79
  80 void chunkqueue_remove_finished_chunks(chunkqueue *cq);
  81
  82 void chunkqueue_steal(chunkqueue *dest, chunkqueue *src, off_t len);
  83 struct server;
  84 int chunkqueue_steal_with_tempfiles(struct server *srv, chunkqueue *dest, chunkqueue *src, off_t len);
  85
  86 off_t chunkqueue_length(chunkqueue *cq);
  87 void chunkqueue_free(chunkqueue *cq);
  88 void chunkqueue_reset(chunkqueue *cq);
  89
  90 int chunkqueue_is_empty(chunkqueue *cq);
  91
  92 #endif