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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 17:36:47 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-15 17:36:47 +0000 |
commit | 0441d265f2bb9da249c7abf333f0f771fadb4ab5 (patch) | |
tree | 3f3789daa2f6db22da6e55e92bee0062a7d613fe /src/lib/istream-private.h | |
parent | Initial commit. (diff) | |
download | dovecot-0441d265f2bb9da249c7abf333f0f771fadb4ab5.tar.xz dovecot-0441d265f2bb9da249c7abf333f0f771fadb4ab5.zip |
Adding upstream version 1:2.3.21+dfsg1.upstream/1%2.3.21+dfsg1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/lib/istream-private.h')
-rw-r--r-- | src/lib/istream-private.h | 140 |
1 files changed, 140 insertions, 0 deletions
diff --git a/src/lib/istream-private.h b/src/lib/istream-private.h new file mode 100644 index 0000000..b612b9c --- /dev/null +++ b/src/lib/istream-private.h @@ -0,0 +1,140 @@ +#ifndef ISTREAM_PRIVATE_H +#define ISTREAM_PRIVATE_H + +#include "istream.h" +#include "iostream-private.h" + +#define I_STREAM_MIN_SIZE IO_BLOCK_SIZE + +struct io; + +struct istream_private { +/* inheritance: */ + struct iostream_private iostream; + +/* methods: */ + ssize_t (*read)(struct istream_private *stream); + void (*seek)(struct istream_private *stream, + uoff_t v_offset, bool mark); + void (*sync)(struct istream_private *stream); + int (*stat)(struct istream_private *stream, bool exact); + int (*get_size)(struct istream_private *stream, bool exact, uoff_t *size_r); + void (*switch_ioloop_to)(struct istream_private *stream, + struct ioloop *ioloop); + struct istream_snapshot * + (*snapshot)(struct istream_private *stream, + struct istream_snapshot *prev_snapshot); + +/* data: */ + struct istream istream; + + int fd; + uoff_t start_offset; + struct stat statbuf; + /* added by io_add_istream() -> i_stream_set_io() */ + struct io *io; + + const unsigned char *buffer; + unsigned char *w_buffer; /* may be NULL */ + + size_t buffer_size, max_buffer_size, init_buffer_size, data_limit; + size_t skip, pos; + /* If seeking backwards within the buffer, the next read() will + return again pos..high_pos */ + size_t high_pos; + + struct istream *parent; /* for filter streams */ + uoff_t parent_start_offset; + /* Initially UOFF_T_MAX. Otherwise it's the exact known stream size, + which can be used by stat() / get_size(). */ + uoff_t cached_stream_size; + + /* parent stream's expected offset is kept here. i_stream_read() + always seeks parent stream to here before calling read(). */ + uoff_t parent_expected_offset; + + struct memarea *memarea; + struct istream_snapshot *prev_snapshot; + /* increased every time the stream is changed (e.g. seek, read). + this way streams can check if their parent streams have been + accessed behind them. */ + unsigned int access_counter; + /* Timestamp when read() last returned >0 */ + struct timeval last_read_timeval; + + string_t *line_str; /* for i_stream_next_line() if w_buffer == NULL */ + bool line_crlf:1; + bool return_nolf_line:1; + bool stream_size_passthrough:1; /* stream is parent's size */ + bool nonpersistent_buffers:1; + bool io_pending:1; +}; + +struct istream_snapshot { + struct istream_snapshot *prev_snapshot; + struct memarea *old_memarea; + struct istream *istream; + void (*free)(struct istream_snapshot *snapshot); +}; + +enum istream_create_flag { + /* The stream guarantees that the buffer pointer stays valid when it + returns <= 0. */ + ISTREAM_CREATE_FLAG_NOOP_SNAPSHOT = 0x01, +}; + +struct istream * ATTR_NOWARN_UNUSED_RESULT +i_stream_create(struct istream_private *stream, struct istream *parent, int fd, + enum istream_create_flag flags) ATTR_NULL(2); +/* Initialize parent lazily after i_stream_create() has already been called. */ +void i_stream_init_parent(struct istream_private *_stream, + struct istream *parent); + +void i_stream_compress(struct istream_private *stream); +void i_stream_grow_buffer(struct istream_private *stream, size_t bytes); +bool ATTR_NOWARN_UNUSED_RESULT +i_stream_try_alloc(struct istream_private *stream, + size_t wanted_size, size_t *size_r); +/* Like i_stream_try_alloc(), but compress only if it's the only way to get + more space. This can be useful when stream is marked with + i_stream_seek_mark() */ +bool ATTR_NOWARN_UNUSED_RESULT +i_stream_try_alloc_avoid_compress(struct istream_private *stream, + size_t wanted_size, size_t *size_r); +void *i_stream_alloc(struct istream_private *stream, size_t size); +/* Detach istream from its current memarea. This unreferences the memarea and + resets the w_buffer to empty. This can be used to make sure i_stream_*alloc() + won't return a pointer to memory referenced to in a snapshot. */ +void i_stream_memarea_detach(struct istream_private *stream); +/* Free memory allocated by i_stream_*alloc() */ +void i_stream_free_buffer(struct istream_private *stream); +ssize_t i_stream_read_copy_from_parent(struct istream *istream); +void i_stream_default_seek_nonseekable(struct istream_private *stream, + uoff_t v_offset, bool mark); +/* Returns FALSE if seeking must be done by starting from the beginning. + The caller is then expected to reset the stream and call this function + again, which should work then. If TRUE is returned, the seek was either + successfully done or stream_errno is set. */ +bool i_stream_nonseekable_try_seek(struct istream_private *stream, + uoff_t v_offset); + +/* Default snapshot handling: use memarea if it exists, otherwise snapshot + parent stream. */ +struct istream_snapshot * +i_stream_default_snapshot(struct istream_private *stream, + struct istream_snapshot *prev_snapshot); +void i_stream_snapshot_free(struct istream_snapshot **snapshot); + +struct istream *i_stream_get_root_io(struct istream *stream); +void i_stream_set_io(struct istream *stream, struct io *io); +void i_stream_unset_io(struct istream *stream, struct io *io); + +/* Filter istreams should be calling this instead of i_stream_read() to avoid + unnecessarily referencing memareas. After this call any pointers to the + parent istream's content must be considered as potentially invalid and have + to be updated, even if the return value is <=0. */ +ssize_t i_stream_read_memarea(struct istream *stream); +int i_stream_read_more_memarea(struct istream *stream, + const unsigned char **data_r, size_t *size_r); + +#endif |