topology: improve the printf buffer management

The commit d04e72c9a593015952e4858b92ab3f9d821560d9 introduced
the dynamic printf buffer allocation for each tplg_save_printf()
call.

Introduce 'struct tplg_buf' which carries extra information about
the temporary printf buffer and the destination buffer to save allocation
requests.

The printf buffer is also allocated using 1024 bytes chunks.

A comparison between 'alloc everyting' and 'cache+chunk alloc' for the
random picked topology file:

  1: 18,620 allocs, 18,620 frees, 7,239,688 bytes allocated
  2: 12,490 allocs, 12,490 frees, 962,568 bytes allocated

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/src/topology/channel.c b/src/topology/channel.c
index 47d5ea4..ebdff46 100644 (file)
--- a/src/topology/channel.c
+++ b/src/topology/channel.c
@@ -138,7 +138,8 @@ int tplg_parse_channel(snd_tplg_t *tplg, snd_config_t *cfg,
 
 int tplg_save_channels(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                       struct snd_soc_tplg_channel *channel,
-                      unsigned int count, char **dst, const char *pfx)
+                      unsigned int count, struct tplg_buf *dst,
+                      const char *pfx)
 {
        struct snd_soc_tplg_channel *c;
        const char *s;

diff --git a/src/topology/ctl.c b/src/topology/ctl.c
index 1d31b49..a383996 100644 (file)
--- a/src/topology/ctl.c
+++ b/src/topology/ctl.c
@@ -105,8 +105,8 @@ int parse_access(snd_config_t *cfg,
 
 /* Save Access */
 static int tplg_save_access(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
-                           struct snd_soc_tplg_ctl_hdr *hdr, char **dst,
-                           const char *pfx)
+                           struct snd_soc_tplg_ctl_hdr *hdr,
+                           struct tplg_buf *dst, const char *pfx)
 {
        const char *last;
        unsigned int j, count, access, cval;
@@ -399,7 +399,7 @@ int tplg_parse_tlv(snd_tplg_t *tplg, snd_config_t *cfg,
 /* save TLV data */
 int tplg_save_tlv(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                  struct tplg_elem *elem,
-                 char **dst, const char *pfx)
+                 struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_ctl_tlv *tlv = elem->tlv;
        struct snd_soc_tplg_tlv_dbscale *scale;
@@ -557,7 +557,7 @@ int tplg_parse_control_bytes(snd_tplg_t *tplg,
 /* save control bytes */
 int tplg_save_control_bytes(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                            struct tplg_elem *elem,
-                           char **dst, const char *pfx)
+                           struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_bytes_control *be = elem->bytes_ext;
        char pfx2[16];
@@ -697,7 +697,7 @@ int tplg_parse_control_enum(snd_tplg_t *tplg, snd_config_t *cfg,
 /* save control eunm */
 int tplg_save_control_enum(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                           struct tplg_elem *elem,
-                          char **dst, const char *pfx)
+                          struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_enum_control *ec = elem->enum_ctrl;
        char pfx2[16];
@@ -858,8 +858,8 @@ int tplg_parse_control_mixer(snd_tplg_t *tplg,
 }
 
 int tplg_save_control_mixer(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
-                           struct tplg_elem *elem, char **dst,
-                           const char *pfx)
+                           struct tplg_elem *elem,
+                           struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_mixer_control *mc = elem->mixer_ctrl;
        char pfx2[16];

diff --git a/src/topology/dapm.c b/src/topology/dapm.c
index 73a9390..46f2f8b 100644 (file)
--- a/src/topology/dapm.c
+++ b/src/topology/dapm.c
@@ -416,7 +416,8 @@ int tplg_parse_dapm_graph(snd_tplg_t *tplg, snd_config_t *cfg,
 }
 
 /* save DAPM graph */
-int tplg_save_dapm_graph(snd_tplg_t *tplg, int index, char **dst, const char *pfx)
+int tplg_save_dapm_graph(snd_tplg_t *tplg, int index,
+                        struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_dapm_graph_elem *route;
        struct list_head *pos;
@@ -669,7 +670,7 @@ int tplg_parse_dapm_widget(snd_tplg_t *tplg,
 /* save DAPM widget */
 int tplg_save_dapm_widget(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                          struct tplg_elem *elem,
-                         char **dst, const char *pfx)
+                         struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_dapm_widget *widget = elem->widget;
        const char *s;

diff --git a/src/topology/data.c b/src/topology/data.c
index 5742b35..3585af3 100644 (file)
--- a/src/topology/data.c
+++ b/src/topology/data.c
@@ -121,7 +121,8 @@ int tplg_parse_refs(snd_config_t *cfg, struct tplg_elem *elem,
 /* save references */
 int tplg_save_refs(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                   struct tplg_elem *elem, unsigned int type,
-                  const char *id, char **dst, const char *pfx)
+                  const char *id, struct tplg_buf *dst,
+                  const char *pfx)
 {
        struct tplg_ref *ref, *last;
        struct list_head *pos;
@@ -890,7 +891,7 @@ err:
 /* save tuple set */
 static int tplg_save_tuple_set(struct tplg_vendor_tuples *tuples,
                               unsigned int set_index,
-                              char **dst, const char *pfx)
+                              struct tplg_buf *dst, const char *pfx)
 {
        struct tplg_tuple_set *set;
        struct tplg_tuple *tuple;
@@ -1014,7 +1015,7 @@ static int parse_tuple_sets(snd_config_t *cfg,
 /* save tuple sets */
 int tplg_save_tuple_sets(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                         struct tplg_elem *elem,
-                        char **dst, const char *pfx)
+                        struct tplg_buf *dst, const char *pfx)
 {
        struct tplg_vendor_tuples *tuples = elem->tuples;
        unsigned int i;
@@ -1085,7 +1086,7 @@ int tplg_parse_tokens(snd_tplg_t *tplg, snd_config_t *cfg,
 /* save vendor tokens */
 int tplg_save_tokens(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                     struct tplg_elem *elem,
-                    char **dst, const char *pfx)
+                    struct tplg_buf *dst, const char *pfx)
 {
        struct tplg_vendor_tokens *tokens = elem->tokens;
        unsigned int i;
@@ -1156,7 +1157,7 @@ int tplg_parse_tuples(snd_tplg_t *tplg, snd_config_t *cfg,
 /* save vendor tuples */
 int tplg_save_tuples(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                     struct tplg_elem *elem,
-                    char **dst, const char *pfx)
+                    struct tplg_buf *dst, const char *pfx)
 {
        char pfx2[16];
        int err;
@@ -1242,7 +1243,7 @@ int tplg_parse_manifest_data(snd_tplg_t *tplg, snd_config_t *cfg,
 
 /* save manifest data */
 int tplg_save_manifest_data(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
-                           struct tplg_elem *elem, char **dst,
+                           struct tplg_elem *elem, struct tplg_buf *dst,
                            const char *pfx)
 {
        struct list_head *pos;
@@ -1420,7 +1421,7 @@ int tplg_parse_data(snd_tplg_t *tplg, snd_config_t *cfg,
 /* save data element */
 int tplg_save_data(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                   struct tplg_elem *elem,
-                  char **dst, const char *pfx)
+                  struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_private *priv = elem->data;
        struct list_head *pos;

diff --git a/src/topology/ops.c b/src/topology/ops.c
index 110eef5..da17560 100644 (file)
--- a/src/topology/ops.c
+++ b/src/topology/ops.c
@@ -105,8 +105,8 @@ int tplg_parse_ops(snd_tplg_t *tplg ATTRIBUTE_UNUSED, snd_config_t *cfg,
 
 /* save control operations */
 int tplg_save_ops(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
-                 struct snd_soc_tplg_ctl_hdr *hdr, char **dst,
-                 const char *pfx)
+                 struct snd_soc_tplg_ctl_hdr *hdr,
+                 struct tplg_buf *dst, const char *pfx)
 {
        const char *s;
        int err;
@@ -191,7 +191,7 @@ int tplg_parse_ext_ops(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
 /* save external control operations */
 int tplg_save_ext_ops(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                      struct snd_soc_tplg_bytes_control *be,
-                     char **dst, const char *pfx)
+                     struct tplg_buf *dst, const char *pfx)
 {
        const char *s;
        int err;

diff --git a/src/topology/pcm.c b/src/topology/pcm.c
index a60ba00..191b7a0 100644 (file)
--- a/src/topology/pcm.c
+++ b/src/topology/pcm.c
@@ -538,7 +538,7 @@ int tplg_parse_stream_caps(snd_tplg_t *tplg,
 /* save stream caps */
 int tplg_save_stream_caps(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                          struct tplg_elem *elem,
-                         char **dst, const char *pfx)
+                         struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_stream_caps *sc = elem->stream_caps;
        const char *s;
@@ -686,7 +686,7 @@ static int tplg_parse_streams(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
 /* Save the caps and config of a pcm stream */
 int tplg_save_streams(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                      struct tplg_elem *elem,
-                     char **dst, const char *pfx)
+                     struct tplg_buf *dst, const char *pfx)
 {
        static const char *stream_ids[2] = {
                "playback",
@@ -778,7 +778,7 @@ static int tplg_parse_fe_dai(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
 /* Save the caps and config of a pcm stream */
 int tplg_save_fe_dai(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                     struct tplg_elem *elem,
-                    char **dst, const char *pfx)
+                    struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_pcm *pcm = elem->pcm;
        int err = 0;
@@ -810,7 +810,7 @@ static int parse_flag(snd_config_t *n, unsigned int mask_in,
 }
 
 static int save_flags(unsigned int flags, unsigned int mask,
-                     char **dst, const char *pfx)
+                     struct tplg_buf *dst, const char *pfx)
 {
        static unsigned int flag_masks[3] = {
                SND_SOC_TPLG_LNK_FLGBIT_SYMMETRIC_RATES,
@@ -944,7 +944,7 @@ int tplg_parse_pcm(snd_tplg_t *tplg, snd_config_t *cfg,
 /* save PCM */
 int tplg_save_pcm(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                  struct tplg_elem *elem,
-                 char **dst, const char *pfx)
+                 struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_pcm *pcm = elem->pcm;
        char pfx2[16];
@@ -1081,7 +1081,7 @@ int tplg_parse_dai(snd_tplg_t *tplg, snd_config_t *cfg,
 /* save DAI */
 int tplg_save_dai(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                  struct tplg_elem *elem,
-                 char **dst, const char *pfx)
+                 struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_dai *dai = elem->dai;
        char pfx2[16];
@@ -1235,7 +1235,7 @@ int tplg_parse_link(snd_tplg_t *tplg, snd_config_t *cfg,
 /* save physical link */
 int tplg_save_link(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                   struct tplg_elem *elem,
-                  char **dst, const char *pfx)
+                  struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_link_config *link = elem->link;
        char pfx2[16];
@@ -1315,7 +1315,7 @@ int tplg_parse_cc(snd_tplg_t *tplg, snd_config_t *cfg,
 /* save CC */
 int tplg_save_cc(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                 struct tplg_elem *elem,
-                char **dst, const char *pfx)
+                struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_link_config *link = elem->link;
        char pfx2[16];
@@ -1611,7 +1611,7 @@ int tplg_parse_hw_config(snd_tplg_t *tplg, snd_config_t *cfg,
 /* save hw config */
 int tplg_save_hw_config(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                        struct tplg_elem *elem,
-                       char **dst, const char *pfx)
+                       struct tplg_buf *dst, const char *pfx)
 {
        struct snd_soc_tplg_hw_config *hc = elem->hw_cfg;
        int err;

diff --git a/src/topology/save.c b/src/topology/save.c
index 631d84b..56250af 100644 (file)
--- a/src/topology/save.c
+++ b/src/topology/save.c
@@ -19,25 +19,43 @@
 #include "tplg_local.h"
 
 #define SAVE_ALLOC_SHIFT       (13)    /* 8192 bytes */
-#define PRINT_BUF_SIZE         (1024)
+#define PRINT_ALLOC_SHIFT      (10)    /* 1024 bytes */
 #define PRINT_BUF_SIZE_MAX     (1024 * 1024)
+#define NEXT_CHUNK(val, shift) ((((val) >> (shift)) + 1) << (shift))
 
-int tplg_save_printf(char **dst, const char *pfx, const char *fmt, ...)
+void tplg_buf_init(struct tplg_buf *buf)
+{
+       buf->dst = NULL;
+       buf->dst_len = 0;
+       buf->printf_buf = NULL;
+       buf->printf_buf_size = 0;
+}
+
+void tplg_buf_free(struct tplg_buf *buf)
+{
+       free(buf->dst);
+       free(buf->printf_buf);
+}
+
+char *tplg_buf_detach(struct tplg_buf *buf)
+{
+       char *ret = buf->dst;
+       free(buf->printf_buf);
+       return ret;
+}
+
+int tplg_save_printf(struct tplg_buf *dst, const char *pfx, const char *fmt, ...)
 {
        va_list va;
-       char *buf, *s;
+       char *s;
        size_t n, l, t, pl;
        int ret = 0;
 
-       buf = malloc(PRINT_BUF_SIZE);
-       if (!buf)
-               return -ENOMEM;
-
        if (pfx == NULL)
                pfx = "";
 
        va_start(va, fmt);
-       n = vsnprintf(buf, PRINT_BUF_SIZE, fmt, va);
+       n = vsnprintf(dst->printf_buf, dst->printf_buf_size, fmt, va);
        va_end(va);
 
        if (n >= PRINT_BUF_SIZE_MAX) {
@@ -45,42 +63,41 @@ int tplg_save_printf(char **dst, const char *pfx, const char *fmt, ...)
                goto end;
        }
 
-       if (n >= PRINT_BUF_SIZE) {
-               char *tmp = realloc(buf, n + 1);
-               if (!tmp) {
+       if (n >= dst->printf_buf_size) {
+               t = NEXT_CHUNK(n + 1, PRINT_ALLOC_SHIFT);
+               s = realloc(dst->printf_buf, t);
+               if (!s) {
                        ret = -ENOMEM;
                        goto end;
                }
-               buf = tmp;
+               dst->printf_buf = s;
+               dst->printf_buf_size = t;
                va_start(va, fmt);
-               n = vsnprintf(buf, n + 1, fmt, va);
+               n = vsnprintf(dst->printf_buf, n + 1, fmt, va);
                va_end(va);
        }
 
        pl = strlen(pfx);
-       l = *dst ? strlen(*dst) : 0;
+       l = dst->dst_len;
        t = l + pl + n + 1;
        /* allocate chunks */
-       if (*dst == NULL ||
+       if (dst->dst == NULL ||
            (l >> SAVE_ALLOC_SHIFT) != (t >> SAVE_ALLOC_SHIFT)) {
-               s = realloc(*dst, ((t >> SAVE_ALLOC_SHIFT) + 1) <<
-                                                       SAVE_ALLOC_SHIFT);
+               s = realloc(dst->dst, NEXT_CHUNK(t, SAVE_ALLOC_SHIFT));
                if (s == NULL) {
-                       free(*dst);
-                       *dst = NULL;
                        ret = -ENOMEM;
                        goto end;
                }
        } else {
-               s = *dst;
+               s = dst->dst;
        }
 
        if (pl > 0)
                strcpy(s + l, pfx);
-       strcpy(s + l + pl, buf);
-       *dst = s;
+       strcpy(s + l + pl, dst->printf_buf);
+       dst->dst = s;
+       dst->dst_len = t - 1;
 end:
-       free(buf);
        return ret;
 }
 
@@ -209,7 +226,7 @@ static int tplg_check_quoted(const unsigned char *p)
        return 0;
 }
 
-static int tplg_save_quoted(char **dst, const char *str)
+static int tplg_save_quoted(struct tplg_buf *dst, const char *str)
 {
        static const char nibble[16] = "0123456789abcdef";
        unsigned char *p, *d, *t;
@@ -263,7 +280,7 @@ static int tplg_save_quoted(char **dst, const char *str)
        return tplg_save_printf(dst, NULL, "'%s'", d);
 }
 
-static int tplg_save_string(char **dst, const char *str, int id)
+static int tplg_save_string(struct tplg_buf *dst, const char *str, int id)
 {
        const unsigned char *p = (const unsigned char *)str;
 
@@ -279,7 +296,7 @@ static int tplg_save_string(char **dst, const char *str, int id)
        return tplg_save_printf(dst, NULL, "%s", str);
 }
 
-static int save_config(char **dst, int level, const char *delim, snd_config_t *src)
+static int save_config(struct tplg_buf *dst, int level, const char *delim, snd_config_t *src)
 {
        snd_config_iterator_t i, next;
        snd_config_t *s;
@@ -400,7 +417,8 @@ retval:
        return 0;
 }
 
-static int tplg_save(snd_tplg_t *tplg, char **dst, int gindex, const char *prefix)
+static int tplg_save(snd_tplg_t *tplg, struct tplg_buf *dst,
+                    int gindex, const char *prefix)
 {
        struct tplg_table *tptr;
        struct tplg_elem *elem;
@@ -484,8 +502,6 @@ static int tplg_save(snd_tplg_t *tplg, char **dst, int gindex, const char *prefi
        return 0;
 
 _err:
-       free(*dst);
-       *dst = NULL;
        return err;
 }
 
@@ -540,9 +556,9 @@ static int tplg_index_groups(snd_tplg_t *tplg, int **indexes)
 
 int snd_tplg_save(snd_tplg_t *tplg, char **dst, int flags)
 {
+       struct tplg_buf buf, buf2;
        snd_input_t *in;
        snd_config_t *top, *top2;
-       char *dst2;
        int *indexes, *a;
        int err;
 
@@ -550,35 +566,41 @@ int snd_tplg_save(snd_tplg_t *tplg, char **dst, int flags)
        assert(dst);
        *dst = NULL;
 
+       tplg_buf_init(&buf);
+
        if (flags & SND_TPLG_SAVE_GROUPS) {
                err = tplg_index_groups(tplg, &indexes);
                if (err < 0)
                        return err;
                for (a = indexes; err >= 0 && *a >= 0; a++) {
-                       err = tplg_save_printf(dst, NULL,
+                       err = tplg_save_printf(&buf, NULL,
                                               "IndexGroup.%d {\n",
                                               *a);
                        if (err >= 0)
-                               err = tplg_save(tplg, dst, *a, "\t");
+                               err = tplg_save(tplg, &buf, *a, "\t");
                        if (err >= 0)
-                               err = tplg_save_printf(dst, NULL, "}\n");
+                               err = tplg_save_printf(&buf, NULL, "}\n");
                }
                free(indexes);
        } else {
-               err = tplg_save(tplg, dst, -1, NULL);
+               err = tplg_save(tplg, &buf, -1, NULL);
        }
 
        if (err < 0)
                goto _err;
 
-       if (*dst == NULL)
-               return -EINVAL;
+       if (buf.dst == NULL) {
+               err = -EINVAL;
+               goto _err;
+       }
 
-       if (flags & SND_TPLG_SAVE_NOCHECK)
+       if (flags & SND_TPLG_SAVE_NOCHECK) {
+               *dst = tplg_buf_detach(&buf);
                return 0;
+       }
 
        /* always load configuration - check */
-       err = snd_input_buffer_open(&in, *dst, strlen(*dst));
+       err = snd_input_buffer_open(&in, buf.dst, strlen(buf.dst));
        if (err < 0) {
                SNDERR("could not create input buffer");
                goto _err;
@@ -610,20 +632,20 @@ int snd_tplg_save(snd_tplg_t *tplg, char **dst, int flags)
                top = top2;
        }
 
-       dst2 = NULL;
-       err = save_config(&dst2, 0, NULL, top);
+       tplg_buf_init(&buf2);
+       err = save_config(&buf2, 0, NULL, top);
        snd_config_delete(top);
        if (err < 0) {
                SNDERR("could not save configuration");
                goto _err;
        }
 
-       free(*dst);
-       *dst = dst2;
+       tplg_buf_free(&buf);
+       *dst = tplg_buf_detach(&buf2);
        return 0;
 
 _err:
-       free(*dst);
+       tplg_buf_free(&buf);
        *dst = NULL;
        return err;
 }

diff --git a/src/topology/text.c b/src/topology/text.c
index b899b28..b07feb9 100644 (file)
--- a/src/topology/text.c
+++ b/src/topology/text.c
@@ -93,7 +93,7 @@ int tplg_parse_text(snd_tplg_t *tplg, snd_config_t *cfg,
 /* save text data */
 int tplg_save_text(snd_tplg_t *tplg ATTRIBUTE_UNUSED,
                   struct tplg_elem *elem,
-                  char **dst, const char *pfx)
+                  struct tplg_buf *dst, const char *pfx)
 {
        struct tplg_texts *texts = elem->texts;
        unsigned int i;

diff --git a/src/topology/tplg_local.h b/src/topology/tplg_local.h
index 0c7be20..d553117 100644 (file)
--- a/src/topology/tplg_local.h
+++ b/src/topology/tplg_local.h
@@ -200,6 +200,14 @@ struct map_elem {
        int id;
 };
 
+/* output buffer */
+struct tplg_buf {
+       char *dst;
+       size_t dst_len;
+       char *printf_buf;
+       size_t printf_buf_size;
+};
+
 /* mapping table */
 struct tplg_table {
        const char *name;
@@ -214,9 +222,9 @@ struct tplg_table {
        void (*free)(void *);
        int (*parse)(snd_tplg_t *tplg, snd_config_t *cfg, void *priv);
        int (*save)(snd_tplg_t *tplg, struct tplg_elem *elem,
-                   char **dst, const char *prefix);
+                   struct tplg_buf *dst, const char *prefix);
        int (*gsave)(snd_tplg_t *tplg, int index,
-                    char **dst, const char *prefix);
+                    struct tplg_buf *dst, const char *prefix);
        int (*decod)(snd_tplg_t *tplg, size_t pos,
                     struct snd_soc_tplg_hdr *hdr,
                     void *bin, size_t size);
@@ -348,49 +356,49 @@ int tplg_add_dai_object(snd_tplg_t *tplg, snd_tplg_obj_template_t *t);
 
 int tplg_nice_value_format(char *dst, size_t dst_size, unsigned int value);
 
-int tplg_save_printf(char **dst, const char *prefix, const char *fmt, ...);
+int tplg_save_printf(struct tplg_buf *dst, const char *prefix, const char *fmt, ...);
 int tplg_save_refs(snd_tplg_t *tplg, struct tplg_elem *elem, unsigned int type,
-                  const char *id, char **dst, const char *pfx);
+                  const char *id, struct tplg_buf *dst, const char *pfx);
 int tplg_save_channels(snd_tplg_t *tplg, struct snd_soc_tplg_channel *channel,
-                      unsigned int channel_count, char **dst, const char *pfx);
+                      unsigned int channel_count, struct tplg_buf *dst, const char *pfx);
 int tplg_save_ops(snd_tplg_t *tplg, struct snd_soc_tplg_ctl_hdr *hdr,
-                 char **dst, const char *pfx);
+                 struct tplg_buf *dst, const char *pfx);
 int tplg_save_ext_ops(snd_tplg_t *tplg, struct snd_soc_tplg_bytes_control *be,
-                     char **dst, const char *pfx);
+                     struct tplg_buf *dst, const char *pfx);
 int tplg_save_manifest_data(snd_tplg_t *tplg, struct tplg_elem *elem,
-                           char **dst, const char *pfx);
+                           struct tplg_buf *dst, const char *pfx);
 int tplg_save_control_mixer(snd_tplg_t *tplg, struct tplg_elem *elem,
-                           char **dst, const char *pfx);
+                           struct tplg_buf *dst, const char *pfx);
 int tplg_save_control_enum(snd_tplg_t *tplg, struct tplg_elem *elem,
-                          char **dst, const char *pfx);
+                          struct tplg_buf *dst, const char *pfx);
 int tplg_save_control_bytes(snd_tplg_t *tplg, struct tplg_elem *elem,
-                           char **dst, const char *pfx);
+                           struct tplg_buf *dst, const char *pfx);
 int tplg_save_tlv(snd_tplg_t *tplg, struct tplg_elem *elem,
-                 char **dst, const char *pfx);
+                 struct tplg_buf *dst, const char *pfx);
 int tplg_save_data(snd_tplg_t *tplg, struct tplg_elem *elem,
-                  char **dst, const char *pfx);
+                  struct tplg_buf *dst, const char *pfx);
 int tplg_save_text(snd_tplg_t *tplg, struct tplg_elem *elem,
-                  char **dst, const char *pfx);
+                  struct tplg_buf *dst, const char *pfx);
 int tplg_save_tokens(snd_tplg_t *tplg, struct tplg_elem *elem,
-                    char **dst, const char *pfx);
+                    struct tplg_buf *dst, const char *pfx);
 int tplg_save_tuples(snd_tplg_t *tplg, struct tplg_elem *elem,
-                    char **dst, const char *pfx);
+                    struct tplg_buf *dst, const char *pfx);
 int tplg_save_dapm_graph(snd_tplg_t *tplg, int index,
-                        char **dst, const char *pfx);
+                        struct tplg_buf *dst, const char *pfx);
 int tplg_save_dapm_widget(snd_tplg_t *tplg, struct tplg_elem *elem,
-                         char **dst, const char *pfx);
+                         struct tplg_buf *dst, const char *pfx);
 int tplg_save_link(snd_tplg_t *tplg, struct tplg_elem *elem,
-                  char **dst, const char *pfx);
+                  struct tplg_buf *dst, const char *pfx);
 int tplg_save_cc(snd_tplg_t *tplg, struct tplg_elem *elem,
-                char **dst, const char *pfx);
+                struct tplg_buf *dst, const char *pfx);
 int tplg_save_pcm(snd_tplg_t *tplg, struct tplg_elem *elem,
-                 char **dst, const char *pfx);
+                 struct tplg_buf *dst, const char *pfx);
 int tplg_save_hw_config(snd_tplg_t *tplg, struct tplg_elem *elem,
-                       char **dst, const char *pfx);
+                       struct tplg_buf *dst, const char *pfx);
 int tplg_save_stream_caps(snd_tplg_t *tplg, struct tplg_elem *elem,
-                         char **dst, const char *pfx);
+                         struct tplg_buf *dst, const char *pfx);
 int tplg_save_dai(snd_tplg_t *tplg, struct tplg_elem *elem,
-                 char **dst, const char *pfx);
+                 struct tplg_buf *dst, const char *pfx);
 
 int tplg_decode_template(snd_tplg_t *tplg,
                         size_t pos,