/src/PROJ/curl/lib/bufq.c

Source (jump to first uncovered line)
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * SPDX-License-Identifier: curl
 *
 ***************************************************************************/

#include "curl_setup.h"
#include "bufq.h"

/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"

static bool chunk_is_empty(const struct buf_chunk *chunk)
{
  return chunk->r_offset >= chunk->w_offset;
}

static bool chunk_is_full(const struct buf_chunk *chunk)
{
  return chunk->w_offset >= chunk->dlen;
}

static size_t chunk_len(const struct buf_chunk *chunk)
{
  return chunk->w_offset - chunk->r_offset;
}

static size_t chunk_space(const struct buf_chunk *chunk)
{
  return chunk->dlen - chunk->w_offset;
}

static void chunk_reset(struct buf_chunk *chunk)
{
  chunk->next = NULL;
  chunk->r_offset = chunk->w_offset = 0;
}

static size_t chunk_append(struct buf_chunk *chunk,
                           const unsigned char *buf, size_t len)
{
  unsigned char *p = &chunk->x.data[chunk->w_offset];
  size_t n = chunk->dlen - chunk->w_offset;
  DEBUGASSERT(chunk->dlen >= chunk->w_offset);
  if(n) {
    n = CURLMIN(n, len);
    memcpy(p, buf, n);
    chunk->w_offset += n;
  }
  return n;
}

static size_t chunk_read(struct buf_chunk *chunk,
                         unsigned char *buf, size_t len)
{
  unsigned char *p = &chunk->x.data[chunk->r_offset];
  size_t n = chunk->w_offset - chunk->r_offset;
  DEBUGASSERT(chunk->w_offset >= chunk->r_offset);
  if(!n) {
    return 0;
  }
  else if(n <= len) {
    memcpy(buf, p, n);
    chunk->r_offset = chunk->w_offset = 0;
    return n;
  }
  else {
    memcpy(buf, p, len);
    chunk->r_offset += len;
    return len;
  }
}

static ssize_t chunk_slurpn(struct buf_chunk *chunk, size_t max_len,
                            Curl_bufq_reader *reader,
                            void *reader_ctx, CURLcode *err)
{
  unsigned char *p = &chunk->x.data[chunk->w_offset];
  size_t n = chunk->dlen - chunk->w_offset; /* free amount */
  ssize_t nread;

  DEBUGASSERT(chunk->dlen >= chunk->w_offset);
  if(!n) {
    *err = CURLE_AGAIN;
    return -1;
  }
  if(max_len && n > max_len)
    n = max_len;
  nread = reader(reader_ctx, p, n, err);
  if(nread > 0) {
    DEBUGASSERT((size_t)nread <= n);
    chunk->w_offset += nread;
  }
  return nread;
}

static void chunk_peek(const struct buf_chunk *chunk,
                       const unsigned char **pbuf, size_t *plen)
{
  DEBUGASSERT(chunk->w_offset >= chunk->r_offset);
  *pbuf = &chunk->x.data[chunk->r_offset];
  *plen = chunk->w_offset - chunk->r_offset;
}

static void chunk_peek_at(const struct buf_chunk *chunk, size_t offset,
                          const unsigned char **pbuf, size_t *plen)
{
  offset += chunk->r_offset;
  DEBUGASSERT(chunk->w_offset >= offset);
  *pbuf = &chunk->x.data[offset];
  *plen = chunk->w_offset - offset;
}

static size_t chunk_skip(struct buf_chunk *chunk, size_t amount)
{
  size_t n = chunk->w_offset - chunk->r_offset;
  DEBUGASSERT(chunk->w_offset >= chunk->r_offset);
  if(n) {
    n = CURLMIN(n, amount);
    chunk->r_offset += n;
    if(chunk->r_offset == chunk->w_offset)
      chunk->r_offset = chunk->w_offset = 0;
  }
  return n;
}

static void chunk_list_free(struct buf_chunk **anchor)
{
  struct buf_chunk *chunk;
  while(*anchor) {
    chunk = *anchor;
    *anchor = chunk->next;
    free(chunk);
  }
}



void Curl_bufcp_init(struct bufc_pool *pool,
                     size_t chunk_size, size_t spare_max)
{
  DEBUGASSERT(chunk_size > 0);
  DEBUGASSERT(spare_max > 0);
  memset(pool, 0, sizeof(*pool));
  pool->chunk_size = chunk_size;
  pool->spare_max = spare_max;
}

static CURLcode bufcp_take(struct bufc_pool *pool,
                           struct buf_chunk **pchunk)
{
  struct buf_chunk *chunk = NULL;

  if(pool->spare) {
    chunk = pool->spare;
    pool->spare = chunk->next;
    --pool->spare_count;
    chunk_reset(chunk);
    *pchunk = chunk;
    return CURLE_OK;
  }

  chunk = calloc(1, sizeof(*chunk) + pool->chunk_size);
  if(!chunk) {
    *pchunk = NULL;
    return CURLE_OUT_OF_MEMORY;
  }
  chunk->dlen = pool->chunk_size;
  *pchunk = chunk;
  return CURLE_OK;
}

static void bufcp_put(struct bufc_pool *pool,
                      struct buf_chunk *chunk)
{
  if(pool->spare_count >= pool->spare_max) {
    free(chunk);
  }
  else {
    chunk_reset(chunk);
    chunk->next = pool->spare;
    pool->spare = chunk;
    ++pool->spare_count;
  }
}

void Curl_bufcp_free(struct bufc_pool *pool)
{
  chunk_list_free(&pool->spare);
  pool->spare_count = 0;
}

static void bufq_init(struct bufq *q, struct bufc_pool *pool,
                      size_t chunk_size, size_t max_chunks, int opts)
{
  DEBUGASSERT(chunk_size > 0);
  DEBUGASSERT(max_chunks > 0);
  memset(q, 0, sizeof(*q));
  q->chunk_size = chunk_size;
  q->max_chunks = max_chunks;
  q->pool = pool;
  q->opts = opts;
}

void Curl_bufq_init2(struct bufq *q, size_t chunk_size, size_t max_chunks,
                     int opts)
{
  bufq_init(q, NULL, chunk_size, max_chunks, opts);
}

void Curl_bufq_init(struct bufq *q, size_t chunk_size, size_t max_chunks)
{
  bufq_init(q, NULL, chunk_size, max_chunks, BUFQ_OPT_NONE);
}

void Curl_bufq_initp(struct bufq *q, struct bufc_pool *pool,
                     size_t max_chunks, int opts)
{
  bufq_init(q, pool, pool->chunk_size, max_chunks, opts);
}

void Curl_bufq_free(struct bufq *q)
{
  chunk_list_free(&q->head);
  chunk_list_free(&q->spare);
  q->tail = NULL;
  q->chunk_count = 0;
}

void Curl_bufq_reset(struct bufq *q)
{
  struct buf_chunk *chunk;
  while(q->head) {
    chunk = q->head;
    q->head = chunk->next;
    chunk->next = q->spare;
    q->spare = chunk;
  }
  q->tail = NULL;
}

size_t Curl_bufq_len(const struct bufq *q)
{
  const struct buf_chunk *chunk = q->head;
  size_t len = 0;
  while(chunk) {
    len += chunk_len(chunk);
    chunk = chunk->next;
  }
  return len;
}

size_t Curl_bufq_space(const struct bufq *q)
{
  size_t space = 0;
  if(q->tail)
    space += chunk_space(q->tail);
  if(q->spare) {
    struct buf_chunk *chunk = q->spare;
    while(chunk) {
      space += chunk->dlen;
      chunk = chunk->next;
    }
  }
  if(q->chunk_count < q->max_chunks) {
    space += (q->max_chunks - q->chunk_count) * q->chunk_size;
  }
  return space;
}

bool Curl_bufq_is_empty(const struct bufq *q)
{
  return !q->head || chunk_is_empty(q->head);
}

bool Curl_bufq_is_full(const struct bufq *q)
{
  if(!q->tail || q->spare)
    return FALSE;
  if(q->chunk_count < q->max_chunks)
    return FALSE;
  if(q->chunk_count > q->max_chunks)
    return TRUE;
  /* we have no spares and cannot make more, is the tail full? */
  return chunk_is_full(q->tail);
}

static struct buf_chunk *get_spare(struct bufq *q)
{
  struct buf_chunk *chunk = NULL;

  if(q->spare) {
    chunk = q->spare;
    q->spare = chunk->next;
    chunk_reset(chunk);
    return chunk;
  }

  if(q->chunk_count >= q->max_chunks && (!(q->opts & BUFQ_OPT_SOFT_LIMIT)))
    return NULL;

  if(q->pool) {
    if(bufcp_take(q->pool, &chunk))
      return NULL;
    ++q->chunk_count;
    return chunk;
  }
  else {
    chunk = calloc(1, sizeof(*chunk) + q->chunk_size);
    if(!chunk)
      return NULL;
    chunk->dlen = q->chunk_size;
    ++q->chunk_count;
    return chunk;
  }
}

static void prune_head(struct bufq *q)
{
  struct buf_chunk *chunk;

  while(q->head && chunk_is_empty(q->head)) {
    chunk = q->head;
    q->head = chunk->next;
    if(q->tail == chunk)
      q->tail = q->head;
    if(q->pool) {
      bufcp_put(q->pool, chunk);
      --q->chunk_count;
    }
    else if((q->chunk_count > q->max_chunks) ||
       (q->opts & BUFQ_OPT_NO_SPARES)) {
      /* SOFT_LIMIT allowed us more than max. free spares until
       * we are at max again. Or free them if we are configured
       * to not use spares. */
      free(chunk);
      --q->chunk_count;
    }
    else {
      chunk->next = q->spare;
      q->spare = chunk;
    }
  }
}

static struct buf_chunk *get_non_full_tail(struct bufq *q)
{
  struct buf_chunk *chunk;

  if(q->tail && !chunk_is_full(q->tail))
    return q->tail;
  chunk = get_spare(q);
  if(chunk) {
    /* new tail, and possibly new head */
    if(q->tail) {
      q->tail->next = chunk;
      q->tail = chunk;
    }
    else {
      DEBUGASSERT(!q->head);
      q->head = q->tail = chunk;
    }
  }
  return chunk;
}

ssize_t Curl_bufq_write(struct bufq *q,
                        const unsigned char *buf, size_t len,
                        CURLcode *err)
{
  struct buf_chunk *tail;
  ssize_t nwritten = 0;
  size_t n;

  DEBUGASSERT(q->max_chunks > 0);
  while(len) {
    tail = get_non_full_tail(q);
    if(!tail) {
      if(q->chunk_count < q->max_chunks) {
        *err = CURLE_OUT_OF_MEMORY;
        return -1;
      }
      break;
    }
    n = chunk_append(tail, buf, len);
    if(!n)
      break;
    nwritten += n;
    buf += n;
    len -= n;
  }
  if(nwritten == 0 && len) {
    *err = CURLE_AGAIN;
    return -1;
  }
  *err = CURLE_OK;
  return nwritten;
}

ssize_t Curl_bufq_read(struct bufq *q, unsigned char *buf, size_t len,
                       CURLcode *err)
{
  ssize_t nread = 0;
  size_t n;

  *err = CURLE_OK;
  while(len && q->head) {
    n = chunk_read(q->head, buf, len);
    if(n) {
      nread += n;
      buf += n;
      len -= n;
    }
    prune_head(q);
  }
  if(nread == 0) {
    *err = CURLE_AGAIN;
    return -1;
  }
  return nread;
}

bool Curl_bufq_peek(struct bufq *q,
                    const unsigned char **pbuf, size_t *plen)
{
  if(q->head && chunk_is_empty(q->head)) {
    prune_head(q);
  }
  if(q->head && !chunk_is_empty(q->head)) {
    chunk_peek(q->head, pbuf, plen);
    return TRUE;
  }
  *pbuf = NULL;
  *plen = 0;
  return FALSE;
}

bool Curl_bufq_peek_at(struct bufq *q, size_t offset,
                       const unsigned char **pbuf, size_t *plen)
{
  struct buf_chunk *c = q->head;
  size_t clen;

  while(c) {
    clen = chunk_len(c);
    if(!clen)
      break;
    if(offset >= clen) {
      offset -= clen;
      c = c->next;
      continue;
    }
    chunk_peek_at(c, offset, pbuf, plen);
    return TRUE;
  }
  *pbuf = NULL;
  *plen = 0;
  return FALSE;
}

void Curl_bufq_skip(struct bufq *q, size_t amount)
{
  size_t n;

  while(amount && q->head) {
    n = chunk_skip(q->head, amount);
    amount -= n;
    prune_head(q);
  }
}

ssize_t Curl_bufq_pass(struct bufq *q, Curl_bufq_writer *writer,
                       void *writer_ctx, CURLcode *err)
{
  const unsigned char *buf;
  size_t blen;
  ssize_t nwritten = 0;

  while(Curl_bufq_peek(q, &buf, &blen)) {
    ssize_t chunk_written;

    chunk_written = writer(writer_ctx, buf, blen, err);
    if(chunk_written < 0) {
      if(!nwritten || *err != CURLE_AGAIN) {
        /* blocked on first write or real error, fail */
        nwritten = -1;
      }
      break;
    }
    if(!chunk_written) {
      if(!nwritten) {
        /* treat as blocked */
        *err = CURLE_AGAIN;
        nwritten = -1;
      }
      break;
    }
    Curl_bufq_skip(q, (size_t)chunk_written);
    nwritten += chunk_written;
  }
  return nwritten;
}

ssize_t Curl_bufq_write_pass(struct bufq *q,
                             const unsigned char *buf, size_t len,
                             Curl_bufq_writer *writer, void *writer_ctx,
                             CURLcode *err)
{
  ssize_t nwritten = 0, n;

  *err = CURLE_OK;
  while(len) {
    if(Curl_bufq_is_full(q)) {
      /* try to make room in case we are full */
      n = Curl_bufq_pass(q, writer, writer_ctx, err);
      if(n < 0) {
        if(*err != CURLE_AGAIN) {
          /* real error, fail */
          return -1;
        }
        /* would block, bufq is full, give up */
        break;
      }
    }

    /* Add whatever is remaining now to bufq */
    n = Curl_bufq_write(q, buf, len, err);
    if(n < 0) {
      if(*err != CURLE_AGAIN) {
        /* real error, fail */
        return -1;
      }
      /* no room in bufq */
      break;
    }
    /* edge case of writer returning 0 (and len is >0)
     * break or we might enter an infinite loop here */
    if(n == 0)
      break;

    /* Maybe only part of `data` has been added, continue to loop */
    buf += (size_t)n;
    len -= (size_t)n;
    nwritten += (size_t)n;
  }

  if(!nwritten && len) {
    *err = CURLE_AGAIN;
    return -1;
  }
  *err = CURLE_OK;
  return nwritten;
}

ssize_t Curl_bufq_sipn(struct bufq *q, size_t max_len,
                       Curl_bufq_reader *reader, void *reader_ctx,
                       CURLcode *err)
{
  struct buf_chunk *tail = NULL;
  ssize_t nread;

  *err = CURLE_AGAIN;
  tail = get_non_full_tail(q);
  if(!tail) {
    if(q->chunk_count < q->max_chunks) {
      *err = CURLE_OUT_OF_MEMORY;
      return -1;
    }
    /* full, blocked */
    *err = CURLE_AGAIN;
    return -1;
  }

  nread = chunk_slurpn(tail, max_len, reader, reader_ctx, err);
  if(nread < 0) {
    return -1;
  }
  else if(nread == 0) {
    /* eof */
    *err = CURLE_OK;
  }
  return nread;
}

/**
 * Read up to `max_len` bytes and append it to the end of the buffer queue.
 * if `max_len` is 0, no limit is imposed and the call behaves exactly
 * the same as `Curl_bufq_slurp()`.
 * Returns the total amount of buf read (may be 0) or -1 on other
 * reader errors.
 * Note that even in case of a -1 chunks may have been read and
 * the buffer queue will have different length than before.
 */
static ssize_t bufq_slurpn(struct bufq *q, size_t max_len,
                           Curl_bufq_reader *reader, void *reader_ctx,
                           CURLcode *err)
{
  ssize_t nread = 0, n;

  *err = CURLE_AGAIN;
  while(1) {

    n = Curl_bufq_sipn(q, max_len, reader, reader_ctx, err);
    if(n < 0) {
      if(!nread || *err != CURLE_AGAIN) {
        /* blocked on first read or real error, fail */
        nread = -1;
      }
      else
        *err = CURLE_OK;
      break;
    }
    else if(n == 0) {
      /* eof */
      *err = CURLE_OK;
      break;
    }
    nread += (size_t)n;
    if(max_len) {
      DEBUGASSERT((size_t)n <= max_len);
      max_len -= (size_t)n;
      if(!max_len)
        break;
    }
    /* give up slurping when we get less bytes than we asked for */
    if(q->tail && !chunk_is_full(q->tail))
      break;
  }
  return nread;
}

ssize_t Curl_bufq_slurp(struct bufq *q, Curl_bufq_reader *reader,
                        void *reader_ctx, CURLcode *err)
{
  return bufq_slurpn(q, 0, reader, reader_ctx, err);
}

Coverage Report

Created: 2024-02-25 06:14

Line	Count	Source (jump to first uncovered line)
1		/***************************************************************************
2		* _ _ ____ _
3		* Project ___\| \| \| \| _ \\| \|
4		* / __\| \| \| \| \|_) \| \|
5		* \| (__\| \|_\| \| _ <\| \|___
6		* \___\|\___/\|_\| \_\_____\|
7		*
8		* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9		*
10		* This software is licensed as described in the file COPYING, which
11		* you should have received as part of this distribution. The terms
12		* are also available at https://curl.se/docs/copyright.html.
13		*
14		* You may opt to use, copy, modify, merge, publish, distribute and/or sell
15		* copies of the Software, and permit persons to whom the Software is
16		* furnished to do so, under the terms of the COPYING file.
17		*
18		* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19		* KIND, either express or implied.
20		*
21		* SPDX-License-Identifier: curl
22		*
23		***************************************************************************/
24
25		#include "curl_setup.h"
26		#include "bufq.h"
27
28		/* The last 3 #include files should be in this order */
29		#include "curl_printf.h"
30		#include "curl_memory.h"
31		#include "memdebug.h"
32
33		static bool chunk_is_empty(const struct buf_chunk *chunk)
34	0	{
35	0	return chunk->r_offset >= chunk->w_offset;
36	0	}
37
38		static bool chunk_is_full(const struct buf_chunk *chunk)
39	0	{
40	0	return chunk->w_offset >= chunk->dlen;
41	0	}
42
43		static size_t chunk_len(const struct buf_chunk *chunk)
44	0	{
45	0	return chunk->w_offset - chunk->r_offset;
46	0	}
47
48		static size_t chunk_space(const struct buf_chunk *chunk)
49	0	{
50	0	return chunk->dlen - chunk->w_offset;
51	0	}
52
53		static void chunk_reset(struct buf_chunk *chunk)
54	0	{
55	0	chunk->next = NULL;
56	0	chunk->r_offset = chunk->w_offset = 0;
57	0	}
58
59		static size_t chunk_append(struct buf_chunk *chunk,
60		const unsigned char *buf, size_t len)
61	0	{
62	0	unsigned char *p = &chunk->x.data[chunk->w_offset];
63	0	size_t n = chunk->dlen - chunk->w_offset;
64	0	DEBUGASSERT(chunk->dlen >= chunk->w_offset);
65	0	if(n) {
66	0	n = CURLMIN(n, len);
67	0	memcpy(p, buf, n);
68	0	chunk->w_offset += n;
69	0	}
70	0	return n;
71	0	}
72
73		static size_t chunk_read(struct buf_chunk *chunk,
74		unsigned char *buf, size_t len)
75	0	{
76	0	unsigned char *p = &chunk->x.data[chunk->r_offset];
77	0	size_t n = chunk->w_offset - chunk->r_offset;
78	0	DEBUGASSERT(chunk->w_offset >= chunk->r_offset);
79	0	if(!n) {
80	0	return 0;
81	0	}
82	0	else if(n <= len) {
83	0	memcpy(buf, p, n);
84	0	chunk->r_offset = chunk->w_offset = 0;
85	0	return n;
86	0	}
87	0	else {
88	0	memcpy(buf, p, len);
89	0	chunk->r_offset += len;
90	0	return len;
91	0	}
92	0	}
93
94		static ssize_t chunk_slurpn(struct buf_chunk *chunk, size_t max_len,
95		Curl_bufq_reader *reader,
96		void reader_ctx, CURLcode err)
97	0	{
98	0	unsigned char *p = &chunk->x.data[chunk->w_offset];
99	0	size_t n = chunk->dlen - chunk->w_offset; /* free amount */
100	0	ssize_t nread;
101
102	0	DEBUGASSERT(chunk->dlen >= chunk->w_offset);
103	0	if(!n) {
104	0	*err = CURLE_AGAIN;
105	0	return -1;
106	0	}
107	0	if(max_len && n > max_len)
108	0	n = max_len;
109	0	nread = reader(reader_ctx, p, n, err);
110	0	if(nread > 0) {
111	0	DEBUGASSERT((size_t)nread <= n);
112	0	chunk->w_offset += nread;
113	0	}
114	0	return nread;
115	0	}
116
117		static void chunk_peek(const struct buf_chunk *chunk,
118		const unsigned char *pbuf, size_t plen)
119	0	{
120	0	DEBUGASSERT(chunk->w_offset >= chunk->r_offset);
121	0	*pbuf = &chunk->x.data[chunk->r_offset];
122	0	*plen = chunk->w_offset - chunk->r_offset;
123	0	}
124
125		static void chunk_peek_at(const struct buf_chunk *chunk, size_t offset,
126		const unsigned char *pbuf, size_t plen)
127	0	{
128	0	offset += chunk->r_offset;
129	0	DEBUGASSERT(chunk->w_offset >= offset);
130	0	*pbuf = &chunk->x.data[offset];
131	0	*plen = chunk->w_offset - offset;
132	0	}
133
134		static size_t chunk_skip(struct buf_chunk *chunk, size_t amount)
135	0	{
136	0	size_t n = chunk->w_offset - chunk->r_offset;
137	0	DEBUGASSERT(chunk->w_offset >= chunk->r_offset);
138	0	if(n) {
139	0	n = CURLMIN(n, amount);
140	0	chunk->r_offset += n;
141	0	if(chunk->r_offset == chunk->w_offset)
142	0	chunk->r_offset = chunk->w_offset = 0;
143	0	}
144	0	return n;
145	0	}
146
147		static void chunk_list_free(struct buf_chunk **anchor)
148	0	{
149	0	struct buf_chunk *chunk;
150	0	while(*anchor) {
151	0	chunk = *anchor;
152	0	*anchor = chunk->next;
153	0	free(chunk);
154	0	}
155	0	}
156
157
158
159		void Curl_bufcp_init(struct bufc_pool *pool,
160		size_t chunk_size, size_t spare_max)
161	0	{
162	0	DEBUGASSERT(chunk_size > 0);
163	0	DEBUGASSERT(spare_max > 0);
164	0	memset(pool, 0, sizeof(*pool));
165	0	pool->chunk_size = chunk_size;
166	0	pool->spare_max = spare_max;
167	0	}
168
169		static CURLcode bufcp_take(struct bufc_pool *pool,
170		struct buf_chunk **pchunk)
171	0	{
172	0	struct buf_chunk *chunk = NULL;
173
174	0	if(pool->spare) {
175	0	chunk = pool->spare;
176	0	pool->spare = chunk->next;
177	0	--pool->spare_count;
178	0	chunk_reset(chunk);
179	0	*pchunk = chunk;
180	0	return CURLE_OK;
181	0	}
182
183	0	chunk = calloc(1, sizeof(*chunk) + pool->chunk_size);
184	0	if(!chunk) {
185	0	*pchunk = NULL;
186	0	return CURLE_OUT_OF_MEMORY;
187	0	}
188	0	chunk->dlen = pool->chunk_size;
189	0	*pchunk = chunk;
190	0	return CURLE_OK;
191	0	}
192
193		static void bufcp_put(struct bufc_pool *pool,
194		struct buf_chunk *chunk)
195	0	{
196	0	if(pool->spare_count >= pool->spare_max) {
197	0	free(chunk);
198	0	}
199	0	else {
200	0	chunk_reset(chunk);
201	0	chunk->next = pool->spare;
202	0	pool->spare = chunk;
203	0	++pool->spare_count;
204	0	}
205	0	}
206
207		void Curl_bufcp_free(struct bufc_pool *pool)
208	0	{
209	0	chunk_list_free(&pool->spare);
210	0	pool->spare_count = 0;
211	0	}
212
213		static void bufq_init(struct bufq q, struct bufc_pool pool,
214		size_t chunk_size, size_t max_chunks, int opts)
215	0	{
216	0	DEBUGASSERT(chunk_size > 0);
217	0	DEBUGASSERT(max_chunks > 0);
218	0	memset(q, 0, sizeof(*q));
219	0	q->chunk_size = chunk_size;
220	0	q->max_chunks = max_chunks;
221	0	q->pool = pool;
222	0	q->opts = opts;
223	0	}
224
225		void Curl_bufq_init2(struct bufq *q, size_t chunk_size, size_t max_chunks,
226		int opts)
227	0	{
228	0	bufq_init(q, NULL, chunk_size, max_chunks, opts);
229	0	}
230
231		void Curl_bufq_init(struct bufq *q, size_t chunk_size, size_t max_chunks)
232	0	{
233	0	bufq_init(q, NULL, chunk_size, max_chunks, BUFQ_OPT_NONE);
234	0	}
235
236		void Curl_bufq_initp(struct bufq q, struct bufc_pool pool,
237		size_t max_chunks, int opts)
238	0	{
239	0	bufq_init(q, pool, pool->chunk_size, max_chunks, opts);
240	0	}
241
242		void Curl_bufq_free(struct bufq *q)
243	0	{
244	0	chunk_list_free(&q->head);
245	0	chunk_list_free(&q->spare);
246	0	q->tail = NULL;
247	0	q->chunk_count = 0;
248	0	}
249
250		void Curl_bufq_reset(struct bufq *q)
251	0	{
252	0	struct buf_chunk *chunk;
253	0	while(q->head) {
254	0	chunk = q->head;
255	0	q->head = chunk->next;
256	0	chunk->next = q->spare;
257	0	q->spare = chunk;
258	0	}
259	0	q->tail = NULL;
260	0	}
261
262		size_t Curl_bufq_len(const struct bufq *q)
263	0	{
264	0	const struct buf_chunk *chunk = q->head;
265	0	size_t len = 0;
266	0	while(chunk) {
267	0	len += chunk_len(chunk);
268	0	chunk = chunk->next;
269	0	}
270	0	return len;
271	0	}
272
273		size_t Curl_bufq_space(const struct bufq *q)
274	0	{
275	0	size_t space = 0;
276	0	if(q->tail)
277	0	space += chunk_space(q->tail);
278	0	if(q->spare) {
279	0	struct buf_chunk *chunk = q->spare;
280	0	while(chunk) {
281	0	space += chunk->dlen;
282	0	chunk = chunk->next;
283	0	}
284	0	}
285	0	if(q->chunk_count < q->max_chunks) {
286	0	space += (q->max_chunks - q->chunk_count) * q->chunk_size;
287	0	}
288	0	return space;
289	0	}
290
291		bool Curl_bufq_is_empty(const struct bufq *q)
292	0	{
293	0	return !q->head \|\| chunk_is_empty(q->head);
294	0	}
295
296		bool Curl_bufq_is_full(const struct bufq *q)
297	0	{
298	0	if(!q->tail \|\| q->spare)
299	0	return FALSE;
300	0	if(q->chunk_count < q->max_chunks)
301	0	return FALSE;
302	0	if(q->chunk_count > q->max_chunks)
303	0	return TRUE;
304		/* we have no spares and cannot make more, is the tail full? */
305	0	return chunk_is_full(q->tail);
306	0	}
307
308		static struct buf_chunk get_spare(struct bufq q)
309	0	{
310	0	struct buf_chunk *chunk = NULL;
311
312	0	if(q->spare) {
313	0	chunk = q->spare;
314	0	q->spare = chunk->next;
315	0	chunk_reset(chunk);
316	0	return chunk;
317	0	}
318
319	0	if(q->chunk_count >= q->max_chunks && (!(q->opts & BUFQ_OPT_SOFT_LIMIT)))
320	0	return NULL;
321
322	0	if(q->pool) {
323	0	if(bufcp_take(q->pool, &chunk))
324	0	return NULL;
325	0	++q->chunk_count;
326	0	return chunk;
327	0	}
328	0	else {
329	0	chunk = calloc(1, sizeof(*chunk) + q->chunk_size);
330	0	if(!chunk)
331	0	return NULL;
332	0	chunk->dlen = q->chunk_size;
333	0	++q->chunk_count;
334	0	return chunk;
335	0	}
336	0	}
337
338		static void prune_head(struct bufq *q)
339	0	{
340	0	struct buf_chunk *chunk;
341
342	0	while(q->head && chunk_is_empty(q->head)) {
343	0	chunk = q->head;
344	0	q->head = chunk->next;
345	0	if(q->tail == chunk)
346	0	q->tail = q->head;
347	0	if(q->pool) {
348	0	bufcp_put(q->pool, chunk);
349	0	--q->chunk_count;
350	0	}
351	0	else if((q->chunk_count > q->max_chunks) \|\|
352	0	(q->opts & BUFQ_OPT_NO_SPARES)) {
353		/* SOFT_LIMIT allowed us more than max. free spares until
354		* we are at max again. Or free them if we are configured
355		* to not use spares. */
356	0	free(chunk);
357	0	--q->chunk_count;
358	0	}
359	0	else {
360	0	chunk->next = q->spare;
361	0	q->spare = chunk;
362	0	}
363	0	}
364	0	}
365
366		static struct buf_chunk get_non_full_tail(struct bufq q)
367	0	{
368	0	struct buf_chunk *chunk;
369
370	0	if(q->tail && !chunk_is_full(q->tail))
371	0	return q->tail;
372	0	chunk = get_spare(q);
373	0	if(chunk) {
374		/* new tail, and possibly new head */
375	0	if(q->tail) {
376	0	q->tail->next = chunk;
377	0	q->tail = chunk;
378	0	}
379	0	else {
380	0	DEBUGASSERT(!q->head);
381	0	q->head = q->tail = chunk;
382	0	}
383	0	}
384	0	return chunk;
385	0	}
386
387		ssize_t Curl_bufq_write(struct bufq *q,
388		const unsigned char *buf, size_t len,
389		CURLcode *err)
390	0	{
391	0	struct buf_chunk *tail;
392	0	ssize_t nwritten = 0;
393	0	size_t n;
394
395	0	DEBUGASSERT(q->max_chunks > 0);
396	0	while(len) {
397	0	tail = get_non_full_tail(q);
398	0	if(!tail) {
399	0	if(q->chunk_count < q->max_chunks) {
400	0	*err = CURLE_OUT_OF_MEMORY;
401	0	return -1;
402	0	}
403	0	break;
404	0	}
405	0	n = chunk_append(tail, buf, len);
406	0	if(!n)
407	0	break;
408	0	nwritten += n;
409	0	buf += n;
410	0	len -= n;
411	0	}
412	0	if(nwritten == 0 && len) {
413	0	*err = CURLE_AGAIN;
414	0	return -1;
415	0	}
416	0	*err = CURLE_OK;
417	0	return nwritten;
418	0	}
419
420		ssize_t Curl_bufq_read(struct bufq q, unsigned char buf, size_t len,
421		CURLcode *err)
422	0	{
423	0	ssize_t nread = 0;
424	0	size_t n;
425
426	0	*err = CURLE_OK;
427	0	while(len && q->head) {
428	0	n = chunk_read(q->head, buf, len);
429	0	if(n) {
430	0	nread += n;
431	0	buf += n;
432	0	len -= n;
433	0	}
434	0	prune_head(q);
435	0	}
436	0	if(nread == 0) {
437	0	*err = CURLE_AGAIN;
438	0	return -1;
439	0	}
440	0	return nread;
441	0	}
442
443		bool Curl_bufq_peek(struct bufq *q,
444		const unsigned char *pbuf, size_t plen)
445	0	{
446	0	if(q->head && chunk_is_empty(q->head)) {
447	0	prune_head(q);
448	0	}
449	0	if(q->head && !chunk_is_empty(q->head)) {
450	0	chunk_peek(q->head, pbuf, plen);
451	0	return TRUE;
452	0	}
453	0	*pbuf = NULL;
454	0	*plen = 0;
455	0	return FALSE;
456	0	}
457
458		bool Curl_bufq_peek_at(struct bufq *q, size_t offset,
459		const unsigned char *pbuf, size_t plen)
460	0	{
461	0	struct buf_chunk *c = q->head;
462	0	size_t clen;
463
464	0	while(c) {
465	0	clen = chunk_len(c);
466	0	if(!clen)
467	0	break;
468	0	if(offset >= clen) {
469	0	offset -= clen;
470	0	c = c->next;
471	0	continue;
472	0	}
473	0	chunk_peek_at(c, offset, pbuf, plen);
474	0	return TRUE;
475	0	}
476	0	*pbuf = NULL;
477	0	*plen = 0;
478	0	return FALSE;
479	0	}
480
481		void Curl_bufq_skip(struct bufq *q, size_t amount)
482	0	{
483	0	size_t n;
484
485	0	while(amount && q->head) {
486	0	n = chunk_skip(q->head, amount);
487	0	amount -= n;
488	0	prune_head(q);
489	0	}
490	0	}
491
492		ssize_t Curl_bufq_pass(struct bufq q, Curl_bufq_writer writer,
493		void writer_ctx, CURLcode err)
494	0	{
495	0	const unsigned char *buf;
496	0	size_t blen;
497	0	ssize_t nwritten = 0;
498
499	0	while(Curl_bufq_peek(q, &buf, &blen)) {
500	0	ssize_t chunk_written;
501
502	0	chunk_written = writer(writer_ctx, buf, blen, err);
503	0	if(chunk_written < 0) {
504	0	if(!nwritten \|\| *err != CURLE_AGAIN) {
505		/* blocked on first write or real error, fail */
506	0	nwritten = -1;
507	0	}
508	0	break;
509	0	}
510	0	if(!chunk_written) {
511	0	if(!nwritten) {
512		/* treat as blocked */
513	0	*err = CURLE_AGAIN;
514	0	nwritten = -1;
515	0	}
516	0	break;
517	0	}
518	0	Curl_bufq_skip(q, (size_t)chunk_written);
519	0	nwritten += chunk_written;
520	0	}
521	0	return nwritten;
522	0	}
523
524		ssize_t Curl_bufq_write_pass(struct bufq *q,
525		const unsigned char *buf, size_t len,
526		Curl_bufq_writer writer, void writer_ctx,
527		CURLcode *err)
528	0	{
529	0	ssize_t nwritten = 0, n;
530
531	0	*err = CURLE_OK;
532	0	while(len) {
533	0	if(Curl_bufq_is_full(q)) {
534		/* try to make room in case we are full */
535	0	n = Curl_bufq_pass(q, writer, writer_ctx, err);
536	0	if(n < 0) {
537	0	if(*err != CURLE_AGAIN) {
538		/* real error, fail */
539	0	return -1;
540	0	}
541		/* would block, bufq is full, give up */
542	0	break;
543	0	}
544	0	}
545
546		/* Add whatever is remaining now to bufq */
547	0	n = Curl_bufq_write(q, buf, len, err);
548	0	if(n < 0) {
549	0	if(*err != CURLE_AGAIN) {
550		/* real error, fail */
551	0	return -1;
552	0	}
553		/* no room in bufq */
554	0	break;
555	0	}
556		/* edge case of writer returning 0 (and len is >0)
557		* break or we might enter an infinite loop here */
558	0	if(n == 0)
559	0	break;
560
561		/* Maybe only part of `data` has been added, continue to loop */
562	0	buf += (size_t)n;
563	0	len -= (size_t)n;
564	0	nwritten += (size_t)n;
565	0	}
566
567	0	if(!nwritten && len) {
568	0	*err = CURLE_AGAIN;
569	0	return -1;
570	0	}
571	0	*err = CURLE_OK;
572	0	return nwritten;
573	0	}
574
575		ssize_t Curl_bufq_sipn(struct bufq *q, size_t max_len,
576		Curl_bufq_reader reader, void reader_ctx,
577		CURLcode *err)
578	0	{
579	0	struct buf_chunk *tail = NULL;
580	0	ssize_t nread;
581
582	0	*err = CURLE_AGAIN;
583	0	tail = get_non_full_tail(q);
584	0	if(!tail) {
585	0	if(q->chunk_count < q->max_chunks) {
586	0	*err = CURLE_OUT_OF_MEMORY;
587	0	return -1;
588	0	}
589		/* full, blocked */
590	0	*err = CURLE_AGAIN;
591	0	return -1;
592	0	}
593
594	0	nread = chunk_slurpn(tail, max_len, reader, reader_ctx, err);
595	0	if(nread < 0) {
596	0	return -1;
597	0	}
598	0	else if(nread == 0) {
599		/* eof */
600	0	*err = CURLE_OK;
601	0	}
602	0	return nread;
603	0	}
604
605		/**
606		* Read up to `max_len` bytes and append it to the end of the buffer queue.
607		* if `max_len` is 0, no limit is imposed and the call behaves exactly
608		* the same as `Curl_bufq_slurp()`.
609		* Returns the total amount of buf read (may be 0) or -1 on other
610		* reader errors.
611		* Note that even in case of a -1 chunks may have been read and
612		* the buffer queue will have different length than before.
613		*/
614		static ssize_t bufq_slurpn(struct bufq *q, size_t max_len,
615		Curl_bufq_reader reader, void reader_ctx,
616		CURLcode *err)
617	0	{
618	0	ssize_t nread = 0, n;
619
620	0	*err = CURLE_AGAIN;
621	0	while(1) {
622
623	0	n = Curl_bufq_sipn(q, max_len, reader, reader_ctx, err);
624	0	if(n < 0) {
625	0	if(!nread \|\| *err != CURLE_AGAIN) {
626		/* blocked on first read or real error, fail */
627	0	nread = -1;
628	0	}
629	0	else
630	0	*err = CURLE_OK;
631	0	break;
632	0	}
633	0	else if(n == 0) {
634		/* eof */
635	0	*err = CURLE_OK;
636	0	break;
637	0	}
638	0	nread += (size_t)n;
639	0	if(max_len) {
640	0	DEBUGASSERT((size_t)n <= max_len);
641	0	max_len -= (size_t)n;
642	0	if(!max_len)
643	0	break;
644	0	}
645		/* give up slurping when we get less bytes than we asked for */
646	0	if(q->tail && !chunk_is_full(q->tail))
647	0	break;
648	0	}
649	0	return nread;
650	0	}
651
652		ssize_t Curl_bufq_slurp(struct bufq q, Curl_bufq_reader reader,
653		void reader_ctx, CURLcode err)
654	0	{
655	0	return bufq_slurpn(q, 0, reader, reader_ctx, err);
656	0	}