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HPACK post -05 updates
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* Use 1 Huffman code table for both request and response
* Remove complicated deflater side table size management
* Add encoding context update
* Fix memory leak in inflater
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@tatsuhiro-t
tatsuhiro-t committed Feb 13, 2014
1 parent 082876d commit fd88c61
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Showing 19 changed files with 471 additions and 5,771 deletions.
339 changes: 175 additions & 164 deletions lib/nghttp2_hd.c
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106 changes: 49 additions & 57 deletions lib/nghttp2_hd.h
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Original file line number Diff line number Diff line change
Expand Up @@ -22,8 +22,8 @@
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef NGHTTP2_HD_COMP_H
#define NGHTTP2_HD_COMP_H
#ifndef NGHTTP2_HD_H
#define NGHTTP2_HD_H

#ifdef HAVE_CONFIG_H
# include <config.h>
Expand All @@ -48,11 +48,6 @@
encoder only uses the memory up to this value. */
#define NGHTTP2_HD_DEFAULT_MAX_DEFLATE_BUFFER_SIZE (1 << 12)

typedef enum {
NGHTTP2_HD_SIDE_REQUEST = 0,
NGHTTP2_HD_SIDE_RESPONSE = 1
} nghttp2_hd_side;

typedef enum {
NGHTTP2_HD_ROLE_DEFLATE,
NGHTTP2_HD_ROLE_INFLATE
Expand Down Expand Up @@ -108,6 +103,8 @@ typedef enum {

typedef enum {
NGHTTP2_HD_STATE_OPCODE,
NGHTTP2_HD_STATE_CONTEXT_UPDATE,
NGHTTP2_HD_STATE_READ_TABLE_SIZE,
NGHTTP2_HD_STATE_READ_INDEX,
NGHTTP2_HD_STATE_NEWNAME_CHECK_NAMELEN,
NGHTTP2_HD_STATE_NEWNAME_READ_NAMELEN,
Expand All @@ -126,30 +123,10 @@ typedef struct {
is the sum of length of name/value in hd_table +
NGHTTP2_HD_ENTRY_OVERHEAD bytes overhead per each entry. */
size_t hd_table_bufsize;
/* The header table size for decoding. If the context is initialized
as encoder, this value is advertised by remote endpoint
decoder. */
/* The effective header table size. */
size_t hd_table_bufsize_max;
/* The current effective header table size for encoding. This value
is always equal to |hd_table_bufsize| on decoder
context. |deflate_hd_table_bufsize| <= |hd_table_bufsize| must be
hold. */
size_t deflate_hd_table_bufsize;
/* The maximum effective header table for encoding. Although header
table size is bounded by |hd_table_bufsize_max|, the encoder can
use smaller buffer by not retaining the header name/values beyond
the |deflate_hd_table_bufsize_max| and not referencing those
entries. This value is always equal to |hd_table_bufsize_max| on
decoder context. */
size_t deflate_hd_table_bufsize_max;
/* The number of effective entry in |hd_table|. This value is always
equal to hd_table.len on decoder side. */
size_t deflate_hd_tablelen;
/* Role of this context; deflate or infalte */
nghttp2_hd_role role;
/* NGHTTP2_HD_SIDE_REQUEST for processing request, otherwise
response. */
nghttp2_hd_side side;
/* If inflate/deflate error occurred, this value is set to 1 and
further invocation of inflate/deflate will fail with
NGHTTP2_ERR_HEADER_COMP. */
Expand All @@ -158,6 +135,8 @@ typedef struct {

typedef struct {
nghttp2_hd_context ctx;
/* The upper limit of the header table size the deflater accepts. */
size_t deflate_hd_table_bufsize_max;
/* Set to this nonzero to clear reference set on each deflation each
time. */
uint8_t no_refset;
Expand Down Expand Up @@ -189,6 +168,9 @@ typedef struct {
/* The index of header table to toggle off the entry from reference
set at the end of decompression. */
size_t end_headers_index;
/* The maximum header table size the inflater supports. This is the
same value transmitted in SETTINGS_HEADER_TABLE_SIZE */
size_t settings_hd_table_bufsize_max;
nghttp2_hd_opcode opcode;
nghttp2_hd_inflate_state state;
/* nonzero if string is huffman encoded */
Expand Down Expand Up @@ -230,8 +212,7 @@ void nghttp2_hd_entry_free(nghttp2_hd_entry *ent);
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
int nghttp2_hd_deflate_init(nghttp2_hd_deflater *deflater,
nghttp2_hd_side side);
int nghttp2_hd_deflate_init(nghttp2_hd_deflater *deflater);

/*
* Initializes |deflater| for deflating name/values pairs.
Expand All @@ -247,7 +228,6 @@ int nghttp2_hd_deflate_init(nghttp2_hd_deflater *deflater,
* Out of memory.
*/
int nghttp2_hd_deflate_init2(nghttp2_hd_deflater *deflater,
nghttp2_hd_side side,
size_t deflate_hd_table_bufsize_max);

/*
Expand All @@ -259,8 +239,7 @@ int nghttp2_hd_deflate_init2(nghttp2_hd_deflater *deflater,
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
int nghttp2_hd_inflate_init(nghttp2_hd_inflater *inflater,
nghttp2_hd_side side);
int nghttp2_hd_inflate_init(nghttp2_hd_inflater *inflater);

/*
* Deallocates any resources allocated for |deflater|.
Expand All @@ -282,19 +261,37 @@ void nghttp2_hd_deflate_set_no_refset(nghttp2_hd_deflater *deflater,
uint8_t no_refset);

/*
* Changes header table size in |context|. This may trigger eviction
* in the dynamic table.
* Changes header table size of the |deflater|. This may trigger
* eviction in the dynamic table.
*
* This function can be used for deflater and inflater.
* The |settings_hd_table_bufsize_max| should be the value received in
* SETTINGS_HEADER_TABLE_SIZE.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
int nghttp2_hd_change_table_size(nghttp2_hd_context *context,
size_t hd_table_bufsize_max);
int nghttp2_hd_deflate_change_table_size(nghttp2_hd_deflater *deflater,
size_t settings_hd_table_bufsize_max);

/*
* Changes header table size in the |inflater|. This may trigger
* eviction in the dynamic table.
*
* The |settings_hd_table_bufsize_max| should be the value transmitted
* in SETTINGS_HEADER_TABLE_SIZE.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
int nghttp2_hd_inflate_change_table_size(nghttp2_hd_inflater *inflater,
size_t settings_hd_table_bufsize_max);


/*
* Deflates the |nva|, which has the |nvlen| name/value pairs, into
Expand Down Expand Up @@ -379,14 +376,16 @@ int nghttp2_hd_inflate_end_headers(nghttp2_hd_inflater *inflater);
int nghttp2_hd_emit_indname_block(uint8_t **buf_ptr, size_t *buflen_ptr,
size_t *offset_ptr, size_t index,
const uint8_t *value, size_t valuelen,
int inc_indexing,
nghttp2_hd_side side);
int inc_indexing);

/* For unittesting purpose */
int nghttp2_hd_emit_newname_block(uint8_t **buf_ptr, size_t *buflen_ptr,
size_t *offset_ptr, nghttp2_nv *nv,
int inc_indexing,
nghttp2_hd_side side);
int inc_indexing);

/* For unittesting purpose */
int nghttp2_hd_emit_table_size(uint8_t **buf_ptr, size_t *buflen_ptr,
size_t *offset_ptr, size_t table_size);

/* For unittesting purpose */
nghttp2_hd_entry* nghttp2_hd_table_get(nghttp2_hd_context *context,
Expand All @@ -395,37 +394,30 @@ nghttp2_hd_entry* nghttp2_hd_table_get(nghttp2_hd_context *context,
/* Huffman encoding/decoding functions */

/*
* Counts the required bytes to encode |src| with length |len|. If
* |side| is NGHTTP2_HD_SIDE_REQUEST, the request huffman code table
* is used. Otherwise, the response code table is used.
* Counts the required bytes to encode |src| with length |len|.
*
* This function returns the number of required bytes to encode given
* data, including padding of prefix of terminal symbol code. This
* function always succeeds.
*/
size_t nghttp2_hd_huff_encode_count(const uint8_t *src, size_t len,
nghttp2_hd_side side);
size_t nghttp2_hd_huff_encode_count(const uint8_t *src, size_t len);

/*
* Encodes the given data |src| with length |srclen| to the given
* memory location pointed by |dest|, allocated at lest |destlen|
* bytes. The caller is responsible to specify |destlen| at least the
* length that nghttp2_hd_huff_encode_count() returns. If |side| is
* NGHTTP2_HD_SIDE_REQUEST, the request huffman code table is
* used. Otherwise, the response code table is used.
* length that nghttp2_hd_huff_encode_count() returns.
*
* This function returns the number of written bytes, including
* padding of prefix of terminal symbol code. This return value is
* exactly the same with the return value of
* nghttp2_hd_huff_encode_count() if it is given with the same |src|,
* |srclen|, and |side|. This function always succeeds.
* nghttp2_hd_huff_encode_count() if it is given with the same |src|
* and |srclen|. This function always succeeds.
*/
ssize_t nghttp2_hd_huff_encode(uint8_t *dest, size_t destlen,
const uint8_t *src, size_t srclen,
nghttp2_hd_side side);
const uint8_t *src, size_t srclen);

void nghttp2_hd_huff_decode_context_init(nghttp2_hd_huff_decode_context *ctx,
nghttp2_hd_side side);
void nghttp2_hd_huff_decode_context_init(nghttp2_hd_huff_decode_context *ctx);

/*
* Decodes the given data |src| with length |srclen|. The |ctx| must
Expand Down Expand Up @@ -453,4 +445,4 @@ ssize_t nghttp2_hd_huff_decode(nghttp2_hd_huff_decode_context *ctx,
nghttp2_buffer *dest,
const uint8_t *src, size_t srclen, int final);

#endif /* NGHTTP2_HD_COMP_H */
#endif /* NGHTTP2_HD_H */
35 changes: 6 additions & 29 deletions lib/nghttp2_hd_huffman.c
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Original file line number Diff line number Diff line change
Expand Up @@ -30,11 +30,8 @@

#include "nghttp2_hd.h"

extern const nghttp2_huff_sym req_huff_sym_table[];
extern const nghttp2_huff_decode req_huff_decode_table[][16];

extern const nghttp2_huff_sym res_huff_sym_table[];
extern const nghttp2_huff_decode res_huff_decode_table[][16];
extern const nghttp2_huff_sym huff_sym_table[];
extern const nghttp2_huff_decode huff_decode_table[][16];

/*
* Encodes huffman code |sym| into |*dest_ptr|, whose least |rembits|
Expand Down Expand Up @@ -65,18 +62,11 @@ static size_t huff_encode_sym(uint8_t **dest_ptr, size_t rembits,
return rembits;
}

size_t nghttp2_hd_huff_encode_count(const uint8_t *src, size_t len,
nghttp2_hd_side side)
size_t nghttp2_hd_huff_encode_count(const uint8_t *src, size_t len)
{
size_t i;
size_t nbits = 0;
const nghttp2_huff_sym *huff_sym_table;

if(side == NGHTTP2_HD_SIDE_REQUEST) {
huff_sym_table = req_huff_sym_table;
} else {
huff_sym_table = res_huff_sym_table;
}
for(i = 0; i < len; ++i) {
nbits += huff_sym_table[src[i]].nbits;
}
Expand All @@ -85,19 +75,12 @@ size_t nghttp2_hd_huff_encode_count(const uint8_t *src, size_t len,
}

ssize_t nghttp2_hd_huff_encode(uint8_t *dest, size_t destlen,
const uint8_t *src, size_t srclen,
nghttp2_hd_side side)
const uint8_t *src, size_t srclen)
{
int rembits = 8;
uint8_t *dest_first = dest;
size_t i;
const nghttp2_huff_sym *huff_sym_table;

if(side == NGHTTP2_HD_SIDE_REQUEST) {
huff_sym_table = req_huff_sym_table;
} else {
huff_sym_table = res_huff_sym_table;
}
for(i = 0; i < srclen; ++i) {
const nghttp2_huff_sym *sym = &huff_sym_table[src[i]];
if(rembits == 8) {
Expand All @@ -114,14 +97,8 @@ ssize_t nghttp2_hd_huff_encode(uint8_t *dest, size_t destlen,
return dest - dest_first;
}

void nghttp2_hd_huff_decode_context_init(nghttp2_hd_huff_decode_context *ctx,
nghttp2_hd_side side)
void nghttp2_hd_huff_decode_context_init(nghttp2_hd_huff_decode_context *ctx)
{
if(side == NGHTTP2_HD_SIDE_REQUEST) {
ctx->huff_decode_table = req_huff_decode_table;
} else {
ctx->huff_decode_table = res_huff_decode_table;
}
ctx->state = 0;
ctx->accept = 1;
}
Expand All @@ -137,7 +114,7 @@ ssize_t nghttp2_hd_huff_decode(nghttp2_hd_huff_decode_context *ctx,
for(i = 0; i < srclen; ++i) {
uint8_t in = src[i] >> 4;
for(j = 0; j < 2; ++j) {
const nghttp2_huff_decode *t = &ctx->huff_decode_table[ctx->state][in];
const nghttp2_huff_decode *t = &huff_decode_table[ctx->state][in];
if(t->state == -1) {
return NGHTTP2_ERR_HEADER_COMP;
}
Expand Down
1 change: 0 additions & 1 deletion lib/nghttp2_hd_huffman.h
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Original file line number Diff line number Diff line change
Expand Up @@ -52,7 +52,6 @@ typedef struct {
typedef nghttp2_huff_decode huff_decode_table_type[16];

typedef struct {
const huff_decode_table_type *huff_decode_table;
/* Current huffman decoding state. We stripped leaf nodes, so the
value range is [0..255], inclusive. */
uint8_t state;
Expand Down
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